The same evidence that anyone without a time machine has. Zero.
Okay, you keep basing your “reality” on “zero” evidence.
I’ll base mine on U.S. history since about, oh, the 1830’s.
Sorry, but in the United States,—
(1) the winner-take-all system at the national level,
(2) the fact that candidates must win a majority of Electoral College votes to win the election,
(3) and the fact that, if no candidate receives a majority of the vote, the Constitution requires the House of Representatives to decide the Election (and no third party—even Teddy Roosevelt’s-—has fielded more than a handful of candidates for Congress) - - -
make it highly unlikely (shall we say, UNREALISTIC) to conclude that a third party candidate can win the presidency in 2008.
One doesn’t need a time machine to see into the future. One only needs to learn from history and from studying our system to know what the real odds are.