Erick Erickson opposes the Republican National Committee's purity test because the voters should decide.
Riley Crane built a platform for viral collaboration to find DARPA's 10 red balloons randomly placed around the United States.
Charles Moore talks about the garbage patch that's turning the Pacific Ocean into a plastic wasteland.
Barry Scheck explains how the Innocence Project uses DNA evidence to exonerate innocent people. James Fowler talks about the strong influence of social networks and how they affect our lives.
Eugene Jarecki uses "It's a Wonderful Life" to inspire Americans to pull their money out of large banks, while Stephen offers an alternate interpretation of the film. Morgan Freeman, the most trusted voice in America, reads a list of untrustworthy things.
Raj Patel says the hidden cost of our consumption causes a great deal of environmental harm and social destruction.
John Heilemann is confident his book about the 2008 presidential campaign, "Game Change," is as factually accurate as you can imagine.
Kathleen Sebelius discusses her role in the reconciliation of the health care bill between the House and Senate.
Margaret Palmer believes there's a better way to mine for coal than blowing the tops off mountains. Emily Pilloton wants to create things that aren't just well designed, but have a positive social impact.
Stephen needs a clean pint of urine before he can make an Olympic team, and Stephen Bosworth discusses North Korea.
Dick Ebersol invites Stephen to cover the Olympics as a member of the NBC team and receives a check from the Colbert Nation.
John Farmer reveals that the government misrepresented the responsiveness of the national command structure on 9/11.
Kati Marton explains how she accessed her childhood in Hungary by obtaining secret police files.
Paul Begala believes the Democrats need to do three things: attack, attack, attack. Mika Brzezinski couldn't do anything right when she tried to be the perfect wife, mother and journalist.
Arthur Benjamin loves to combine his passions of math and magic to do "mathemagics."
David Gergen believes Obama connected with the younger generation in his State of the Union address, but not the blue-collar workers.
Sport Psychology Consultant Nicole Detling Miller teaches Stephen how to mentally coach Jessica Smith. Harold Ford Jr. maintains his consistent pro-choice position and explains why he changed his mind about gay marriage.
Eliot Spitzer thinks Americans should be furious that the financial system is being rebuilt exactly as it was before the economic collapse.
Peter Cove helps the studio audience get back to work by taking questions and offering advice. John Durant eats like a caveman because our genes are best adapted to a hunter-gatherer diet.
Henry Louis Gates, Jr. informs Stephen that he's the whitest man he's ever tested using genetic analysis.
Jonathan Safran Foer says the U.S. farm system is perfectly antithetical to American values.
George Stephanopoulos discusses his work on "The Week" and "GMA" over a Heineken.
Claire Danes describes her role as an autistic woman who designed a system where cows can walk easily to their death.
Al Michaels will call it a miracle if Shani Davis mouths, "Thank you, Stephen," from the Olympic medal podium. David Ross thinks good Olympic art should contain a heroic individual. With that in mind, Stephen presents his Vancouver poster.
Shaun White theorizes why snowboarders don't burst into tears like figure skaters do when they're judged.
Lindsey Vonn discusses her Austrian cheese remedy for an injured leg and the gender of her skis. Bob Costas climbs up on Stephen's giant moose, Ebersol.
Ski aerialists Ryan St. Onge and Jeret Peterson can't leave until they admit they have an adrenaline addiction.
Shani Davis thanks Stephen Colbert with two Olympic medals around his neck in the dramatic conclusion of a two-part series. Seth Wescott reveals the gentleman's agreement among top snowboarders to wear baggy clothing.
If Don Cheadle really cared about drawing attention to his causes, he'd do heroin for Darfur.
David Brooks compares the Tea Partiers to Wal-Mart hippies and calls Obama a thoughtful guy with a spending problem.
Garry Wills fears that the president's power to declare war puts the Constitution in danger.
Barry Schwartz explains why people are paralyzed with indecision when they're offered too many choices.
Ezra Klein explains the reconciliation process that Democrats need to pass health care reform and what Republicans can do to drag it out. Tom Hanks discusses his role as a history maker and the hard work behind the WWII mini-series, "The Pacific."
Annie Leonard says our quest for more stuff is taking the place of things that provide deeper happiness.
Sean Carroll talks about the mystery of time and the possibility of a multiverse.
David Aaronovitch looks into why intelligent people believe really dumb things about what happens.
Robert Baer wants the troops to get better intelligence from the government, not the private sector.
Rebecca Skloot discusses Henrietta Lacks, whose cells were the first to be immortal and commercialized.
Nell Irvin Painter debates the meaning of white people and arm-wrestles Stephen over the Scots-Irish.
Mary Matalin attempts to explain the Republican position on health care without using talking points.
Claire McCaskill praises the health care reform bill and sends a message to Rush Limbaugh in Costa Rica.
Simon Johnson believes the Obama administration hasn't done enough to prevent another financial crisis.
Craig Mullaney talks about the current military situation and the changing momentum in Afghanistan.
David Frum says it's mathematically impossible for Republicans to repeal and replace the health care bill. Judith Shulevitz thinks the Sabbath teaches us how to organize our time around family and community.
Dean Kamen demonstrates how his prosthetic arm invention helps soldiers feed themselves.
Al Sharpton says education should be about teaching the students, not protecting the principals, teachers and administrators.
David Simon describes his new HBO show, "Treme," as "Glee," but with a few more black people.
Neil deGrasse Tyson says the manned space program is the force that inspires people to become scientists in the first place.
Jeffrey Toobin talks about the legacy of Justice Stevens and his possible Supreme Court replacement. Julian Assange entitled the Apache helicopter video "Collateral Murder" in order to get maximum political impact.
Jon Mooallem discusses the observations of same-sex activities in about 450 different species.
David Shields wants writers to ignore the laws regarding appropriation and create new forms for the 21st century.
Aimee Mullins, who has two prosthetic legs, says the average pinup model has more prosthetics in her breasts than she has on her body.
Andrew Ross Sorkin discusses the importance of the SEC case against Goldman Sachs, which questions whether Wall Street is a casino. George Will talks about the history of baseball, debates health care reform and criticizes Ronald Reagan.
Jeffrey Katzenberg listens to Stephen's movie script idea and presents the newest 3-D glasses.
Craig Robinson's parents liked Barack Obama when they first met him, but they didn't think he would last.
Murdoc calls to tell Stephen he won't be interviewing the real Gorillaz, just Damon Albarn and Jamie Hewlett.
Sharon Jones recalls her old jobs as a corrections officer at Rikers Island and a wedding singer.
Conn Iggulden wants to make it clear that an ordinary person can be a hero, and we can all be inspired by heroic stories.
Instead of another moon landing, Gregg Easterbrook would like to see taxpayer money used to protect Earth against asteroids.
Charlie Crist drops out of Florida's Republican primary, and Abel Maldonado promotes California's Proposition 14. Stephen asks Damian Kulash and Tim Nordwind if they ever make videos with their groupies.
Elizabeth Warren supports financial regulation that will put rules back in place and rein Wall Street in a little bit.
Stephen wishes he had time to talk to Michael J. Fox about his book, "A Funny Thing Happened on the Way to the Future". Mark Moffett describes the elaborate social structures of ants that include market economies and nationalism.
Dave Isay has learned that moms, no matter where they come from, share a lot in common.
Stewart Brand accepts the use of nuclear power because he wants to see us get off all the fossil fuels.
Gary Johnson wants the government to decriminalize marijuana and tell kids the truth about smoking pot.
Hampton Sides talks about what motivated James Earl Ray to assassinate Martin Luther King Jr.
According to Deepak Chopra, Stephen's dark side is arrogance, but his gift is bringing comic relief to America.
Craig Finn and Tad Kubler talk about Heaven, Mother Teresa and their rock prophets.
Ayaan Hirsi Ali wants us to shed the inhibition of judging and say that one religion is better than the other.
Lisa Miller says the problem with the popular belief about Heaven right now is that God isn't there.
Stephen reads Vampire Weekend "The Elements of Style" to prove the necessity of the Oxford comma.
James Carville knows who to blame for the BP oil spill and explains how President Obama should respond to the crisis. Jonathan Alter believes that President Obama made history right after coming into office by preventing another Great Depression.
Mark Frauenfelder demonstrates an all-knowing Twitter orb, the most useless machine and a cigar-box guitar.
Israeli ambassador Michael Oren defends Israel's flotilla raid and explains why he does not support an international investigation into the incident. Sam Nunn hopes to keep nuclear materials out of the hands of terrorists by getting cooperation from other nations.
Alan Bean paints scenes from his time in space to leave behind stories that regular people don't know about.
According to Stephen Prothero, pretending all religions are the same doesn't serve to understand the world.
Carl Safina attributes the BP oil spill to the government protecting corporate greed instead of public interest.
Mark Mothersbaugh and Gerald Casale employed focus groups to help them choose songs, blue hats and suits inspired by Kim Jong-il.
David Mamet believes the theater is dead because they're showing nothing but revivals that weren't good 40 years ago.
Wes Moore speaks to the importance of small decisions and role models by comparing himself to the imprisoned Wes Moore.
Gloria Steinem says men who raise the kids and take care of the house have better marriages, live longer and have better sex.
Tim Westergren describes how Pandora creates a personalized list of songs by analyzing musical attributes.
Michael Specter says everyone gets upset about Big Science and Big Pharma, but they love Big Placebo.
Michael Hastings explains why he wrote the Rolling Stone article that eventually got General Stanley McChrystal fired. John Waters acted out an airplane crash for first graders, and then gave them rat skeletons.
Julian Castro believes Arizona's immigration law comes from legitimate frustration, but the legislation goes overboard.
Nicholas Carr says the Internet short-circuits our mental processes by constantly bombarding us with information.
Manny Howard tried to grow tilapia in his bathtub and almost beat a rabbit to death with a dustpan in self-defense.
Paul Krugman says giving money to the unemployed is a very fast, effective way of creating jobs. Michio Kaku believes we will have something resembling a Harry Potter invisibility cloak within the coming decades.
Garret Keizer says noise and silence get distributed like other forms of wealth and disadvantage.
Steve Carell feels like he's in the witness relocation program, and Jon Stewart wants to escape The Daily Show.
Arturo Rodriguez invites Americans who think immigrant farm workers are taking away jobs to work in the fields.
Hephzibah Anderson discovered what she wanted from sex during her year of abstinence.
Tom Blanton believes Brad Manning may have applied a Facebook mentality when he leaked classified documents about the Afghan war. "The Extra Man" star Kevin Kline is known for his great stage presence, but Stephen will not be out-enunciated by him.
Elon Musk wants to carry people to the space station, but there will be an extra surcharge to bring them back.
Andy Cohen and Stephen re-enact a fight between Bethenny and Kelly from "The Real Housewives of New York City."
Stephen tells Jimmy Cliff that he thinks reggae music is the perfect music for a corporate retreat.
Stephen questions Laura Ingraham about the hackneyed racial stereotypes President Obama makes in his diary.
Michael Posner believes it's in America's best interest to encourage stable democracies that respect human rights.
Savion Glover discusses the origin of tap dancing, explains its decline in popularity and performs with friends.
Dylan Ratigan draws parallels between Mexican drug dealers and American bank executives.
David Finkel spent eight months with troops in Iraq to find out what young Americans go through when they're sent to war.
Chuck Close explains how he paints giant portraits when he has a hard time recognizing faces.
Richard Clarke believes that too many intelligence agencies increase the chances that the next terrorist attack will succeed. Thanks to the Colbert Bump, Mayor John Fetterman has won re-election and Braddock, PA is getting a new community center.
Stephen asks Barry Levine whom he has to sleep with to make it onto the National Enquirer cover.
Spending six years at a zoo made Thomas French start to see people's primal behavior underneath.
Jon Krakauer explains how the Bush administration turned Pat Tillman's death into a propaganda tool.
Leslie Kean describes the hard evidence of UFOs and calls for more investigation.
Jeffrey Goldberg says bad things could come from a decision, either by Israel or the US, to bomb Iran.
Stephen proudly introduces his for-profit college, and Andrew Hacker says online universities are rip-offs. Heidi Cullen attributes the current extreme floods, droughts and heat to global warming.
Richard Engel explains how he got to be the journalist who told the world that Operation Iraqi Freedom was over.
Anthony Romero explains why America needs the ACLU to support the Constitution, now that it has Tea Partiers.
Stephen thanks Yogi Berra, General Ray Odierno, Vice President Joe Biden and the troops in the audience. Stephen welcomes General Ray Odierno back from Iraq with the Colbert Bump and his haircut.
Stephen thanks the veterans with a sexy hot dog man and tries to get them jobs, with Jim Webb's help. Brent Cummings and Josh Bleill appreciate the support they've received from the American public after their tours in Iraq.
Lisa Birnbach defines a preppy as somebody who has a classic outlook on life, as well as a classic wardrobe.
Sean Wilentz explains to the young people, like Stephen, why they should care about Bob Dylan.
In order to solve global warming, Saul Griffith says we have to change our behaviors, not just our technologies.
Lawrence O'Donnell predicts that a Tea Party Congress would get sworn in and immediately move to adjourn for the rest of the year.
Stephen Malkmus explains how Pavement can be such an influential band and not have a number one hit.
Google CEO Eric Schmidt wants people to remember that when you post something online, computers will remember it forever.
Guillermo del Toro has always imagined the National Geographic approach to designing monsters.
Las Vegas Mayor Oscar Goodman remembers his days as a mob lawyer and believes graffiti artists should have their thumbs cut off.
Ken Burns says the steroids era in baseball wasn't as bad as the gambling scandals or the exclusion of African Americans.
Ross Douthat doesn't think Christine O'Donnell's anti-masturbation stance makes for good public policy.
Steven Rattner talks about what would have happened if the Obama administration hadn't bailed out the auto industry.
Aaron Sorkin explains why he didn't go to Harvard, worries about child porn on his hard drive and calls Facebook a performance.
Eugene Robinson sees four categories of black America, and Stephen should feel threatened by all of them.
Leon Botstein has made it mandatory for college freshmen at Bard to take a three-week intensive on a scientific discipline.
Mavis Staples discusses her arranged marriage with Jeff Tweedy, recalls opening for Martin Luther King Jr. and denies singing the devil's music.
Davis Guggenheim explains how America's failing public schools affect Stephen's gated neighborhood.
Robert Reich believes America can't get out of the recession until the circle of prosperity is enlarged for the middle class.
Brendan Steinhauser believes that the Tea Party movement is winning because it's staying on the message of reducing national debt.
Austan Goolsbee says that extending the Bush tax cuts for the wealthy won't pull the American economy out of recession.
Bill Bryson tells the history of the world by questioning the common things we take for granted, in his book, "At Home."
Nicholas Negroponte wants to give laptop computers to children in third-world countries so they can communicate with the rest of the world.
Garry Wills calls himself a disciple of Doris Kearns Goodwin and says the Tea Party movement is a racist endeavor.
Tom Perriello is campaigning on the Democrats' record because he thinks Americans are smart enough to understand that results take time. Apolo Ohno trains like a boxer with a warrior's mentality, but he's still wearing tights skating in circles.
Maira Kalman thinks Abraham Lincoln would have been the most incredible boyfriend.
According to Jonathan Alter, Barack Obama had a more productive first two years than any president since Lyndon Johnson, but the message didn't get out.
David Frum believes the midterm elections are a great opportunity to redirect America onto a more balanced, centrist course.
After the Republican victories in the midterm election, Doris Kearns Goodwin thinks Barack Obama has to figure out how to laugh at himself.
Elvis Costello is ready for the Colbert Bump because his albums don't sell like hotcakes.
According to Reza Aslan, Muslims have decided, in their secret gatherings, to bring down democracy through art.
Cee Lo Green's "F**k You" is so infectious that Stephen feels like he needs to go on a course of Zithromax after he listens to it.
Stephen teaches Martha Stewart how to spread mayonnaise on Wonder Bread and sprinkle the slices with pre-sweetened Kool-Aid mix.
Quincy Jones remembers when Frank Sinatra cut him loose with Lucille Ball and Loretta Young in Las Vegas.
NBA Commissioner David Stern discusses basketball's popularity around the world and the benefits of short shorts.
John Legend encourages people to stay involved and aware of what's going on in the world with his tribute to protest songs from the 60s and 70s.
Ian Frazier describes being on a train for 52 hours and never leaving the Russian forest.
Salvatore Giunta gives credit to all the unsung heroes who didn't receive a Medal of Honor for bravery in Afghanistan.
Dan Savage wants Stephen to set an example for high-profile conservative pundits by making a video for the It Gets Better Project.
Agriculture Secretary Tom Vilsack delivers a Stephen Colbert head made out of 25 pounds of organic cheddar.
Michelle Rhee says the problem with America's public schools is that there is no organized interest group that represents children.
David Stockman wants America to get out of debt by letting the Bush tax cuts expire and cutting the defense budget.
"Doonesbury" cartoonist Garry Trudeau scooped himself on the first openly gay character in a comic strip.
David and Julie Eisenhower talk about what it was like to be with the man who invented the 1950s but didn't know how to use a telephone.
Steve Martin puts his art knowledge to the test by choosing between Ellsworth Kelly's "Green" and a Sherwin-Williams paint swatch.
Julie Taymor agrees that her version of "The Tempest" is "Lost" meets Harry Potter.
Patti Smith gives advice to young people who decide to throw away their lives and become artists.
David Boies supports the Prop 8 challenge because marriage is one of the most important rights in America. Stephen asks Stephen Sondheim if there really is a place for an illegal immigrant like Maria and finishes "Send in the Clowns" with his own lyrics.
While Stephen waits for his Prodigy account to open, Omar Wasow discusses what is at stake in the cyberwar. Laird Hamilton discusses the most dangerous thing in the ocean and the plus side of global warming.
Amy Sedaris shows how to save money by freezing cookie crumbs for the office holiday party. Paul Simon talks about how he sampled a sermon from 1941 for his first Christmas song.
