If Buddy Roemer gets the Americans Elect nomination, and if Gary Johnson gets the Libertarian nomination, and if Virgil Goode gets the Constitution Party nomination, 2012 will be the first presidential election in U.S. history in which five parties each had a presidential nominee, each of whom was also a declared candidate, and each of whom had served either in Congress or as a Governor.
Of course, this presumes that the 2012 Republican nominee will be a person who has served either as a Governor or in Congress.
Another historical note, assuming the candidates named above become nominees, will be that the Libertarian Party will be the second non-major party in U.S. history to have run as many as three presidential nominees, each of whom had once been a Governor or a member of Congress. The three, for the Libertarian Party besides Gary Johnson, are Ron Paul and Bob Barr. The only other minor party that has had at least three former members of Congress, or former Governors, as nominees, is the American Independent Party, which had George Wallace, John Schmitz, Lester Maddox, and John Rarick.