Things are even tougher for House members, such as Ron Paul. His patron saint is James Garfield, the last congressman to jump straight to the presidency, back before the invention of the wheel.

Bill Richardson has the distinct advantage of being a governor, like four of the last five presidents. But he has the misfortune of being a former Cabinet secretary, which is the political equivalent of concrete overshoes. No former Cabinet secretary has made the ascent to the Oval Office since Herbert Hoover in 1928, and he didn't leave anyone yearning for more.

John Edwards lacks that drawback, but he has the handicap of being a former senator, and he has created another for himself: He's running a populist campaign in a country where populists are all glitter and no gold.

Every four years or so, someone emerges with a fiery pitch about helping the little guy and humbling the evil corporate interests. And every time, he's the one who gets a lesson in humility, from Fred Harris (1976) to Dick Gephardt (1988 and 2004) to Pat Buchanan (1992 and 1996) to Al Gore (2000). Perhaps the premier populist in American history, William Jennings Bryan was also the premier loser -- nominated three times for president by the Democratic Party without ever winning.

Recent history suggests that to win the presidency, you have to be a white male from the South or West, preferably with experience as a governor. That description fits only one candidate in the race -- Mike Huckabee. So by examining the portents of history, we find that he's the only person who can possibly be elected next year.

Unless 2008 is one of those years that confirm what Henry Ford insisted: History is bunk.