Now he has a fifth.
Democratic Rep. Bart Gordon of Tennessee said he has sent a nomination packet to the Nobel Committee in honor of Richardson's diplomatic efforts with countries like Sudan and North Korea.
"He's well deserving," said Gordon, who got to know Richardson when they served in Congress together. "It's just a continuation of his willingness to continue to go around the world, whether it's a matter of hostages or other tense situations, and work with all parties."
This year's Nobel prize winner also came from a background in presidential politics; former Vice President Al Gore shared the honor with six scientists for their work to raise awareness about global warming.
A nomination doesn't necessarily mean much. According to the Nobel Committee's database, previous nominees include dictators Joseph Stalin and Benito Mussolini. But Richardson's nomination is a recognition of his unofficial career in international diplomacy as he pursues the top elected office in the United States.
Between campaign stops this year and his job as governor of New Mexico, Richardson went to North Korea to recover the remains of missing U.S. troops from the Korean War and to Sudan to encourage a cease-fire in the Darfur conflict. Richardson often undertakes these efforts on his own, without an official imprimatur from the U.S. government, and he has negotiated with some of the world's most notorious dictators, from Iraq's Saddam Hussein to Cuba's Fidel Castro.
Richardson has touted his past Nobel Peace Prize nominations in at least two campaign commercials, but the Nobel Committee won't verify that since names of nominees are kept secret until 50 years later. Gordon spokeswoman Julie Eubank said her boss was involved in nominations in 2000 and 2001.
Eubank said 11 of Gordon's congressional colleagues signed the nomination letter, including one Republican - Jim Ramstad of Minnesota. Gordon said he's still staying out of the Democratic presidential primary, though.
In a response from his gubernatorial office, Richardson said he was touched by the effort.
"I'm profoundly humbled by this nomination, but I was just trying to do my part," Richardson said. "There are hundreds of dedicated advocates, nonprofits, humanitarian organizations and public servants who work each day to reduce tension in Korea and try to bring peace to Darfur."
Others who signed on to the nomination were Texas Democratic Reps. Charles Gonzalez, Solomon Ortiz, Silvestre Reyes and Ciro Rodriguez; California Democratic Reps. Joe Baca, Xavier Becerra, Bob Filner and Grace Napolitano; and Reps. Eliot Engel of New York, and John Tanner of Tennessee.