Not too long ago, losing presidential candidates packed up their campaign offices and returned, more often than not, to Dirksen, Russell and Hart.
When the 111th Congress convened in January 2009, the former-candidates caucus was anything but an exclusive club. Thirteen former presidential candidates were sworn in, including two who would quickly join the administration—Senators Joe Biden and Hillary Clinton. The 1600 club also included two former nominees ("the Johns"—Senators Kerry and McCain) and nine also-rans (Lamar Alexander, Sam Brownback, Chris Dodd, Tom Harkin, Orrin Hatch, Ted Kennedy, Joe Lieberman, Richard Lugar and Arlen Specter.)
If Kerry is confirmed as secretary of state, the former-candidates caucus will dwindle to four: just Alexander, Harkin, Hatch and McCain remain in the Senate. That's unless former Governor Michael Dukakis changes his mind, and is appointed as the interim senator from Massachusetts.
Of course, club membership could grow again after 2016. Senators Marco Rubio, Rand Paul, Elizabeth Warren and Kirsten Gillibrand can't all be president.