Barack Obama had once promised to run for president in the public financing system, the Watergate-era attempt at reform that which would limit the amounts he could raise and spend. He's been hinting for months that he'd break his promise, and today he did. Obama is a politician -- it's not the first time he's flip-flopped or changed his story (remember the flag pin explanations?...I liked the first version better) and it won't be the last. Despite what the commenters here like to say, Obama isn't running for Messiah, he's a politician running for president against another politician named John McCain. Vote accordingly.
His big mistake wasn't now but making a dumb promise last year. Even Obama didn't realize in 2007 he could do two things at once -- stop taking most lobbyist donations and yet raise a ton of money from energized normal citizens. Ironically, it took some free-market economics -- as practiced by a liberal Democrat -- to create campaign financing in America that actually works.