First, Michele Bachmann knocked out Tim Pawlenty. Then, Rick Perry knocked out Michele Bachmann. Then, Rick Perry knocked out Rick Perry. Then, Paul Ryan decided against running. Then, so did Chris Christie. Has any candidate in recent history been as lucky as Mitt Romney?

Well, yes. In 2004, Blair Hull, the frontrunner in the Democratic primary for the open Senate seat in Illinois, saw his campaign collapse amid allegations that he abused his wife. Then, Jack Ryan, the Republican nominee for the seat, had to withdraw due to a sex scandal with his ex-wife, Jeri Ryan. Then, he was replaced by performance artist Alan Keyes. All of this cleared the way for Barack Obama to win the presidency.

Luck matters in American politics. And right now, Romney seems to have quite a lot of it on his side.