What happened
Barack Obama said Thursday that he would not participate in the public financing system for presidential campaigns—reversing earlier statements and making him the first major party candidate to opt out since the system was created in 1976, after the Watergate scandals. Obama, the presumptive Democratic nominee, said the system had collapsed. An adviser to Obama’s Republican rival, John McCain, said Obama had “broken his word.” (The New York Times)

What the commentators said
There’s a good reason for Obama to change his mind, said Kenneth P. Vogel in Politico. By turning down the $84 million in public money, he’ll also sidestep the $84 million spending limit. His record-breaking fundraising ability, with a possible boost from primary-season rival Hillary Clinton’s backers, could land him $500 million in contributions, which would allow him to pursue an unprecedented 50-state campaign that would force the GOP to spend money in even the reddest states.

“The financial edge, rare for a Democrat to enjoy, was simply too attractive to pass up,” said John Harwood in CNBC’s Political Capital blog. But now Obama will take heat from McCain for “breaking his commitment.” Obama’s defense is that McCain has so many friends in special interest groups that he will get help outside the system. It won’t be easy for “Obama—who has run, like McCain, as a straight-talking reformer”—to make that explanation stick with voters.

That’s an understatement, said Jim Geraghty in National Review Online’s The Campaign Spot blog. Obama said unequivocally in February that he would take public financing if the Republican nominee did the same, yet the McCain camp says he never even contacted them about the matter. “The man makes promises he has no intention of keeping.”