It isn't often that the White House press secretary begins a briefing by saying his boss was wrong.But that's what Jay Carney did Monday in saying that Barack Obama should not have voted against raising the debt ceiling when he was a senator.The president "regrets that vote and thinks it was a mistake," Carney said.How convenient. The difference, of course, is that Obama cast his protest vote during the Bush administration, and now he needs Republican votes in the coming weeks to avoid having the U.S. government default on its debts.That, said Carney, would be a "catastrophic folly," "devastating" to jobs and growth, with "Armageddon-like" consequences for the economy.The periodic jousting over the debt ceiling--which will, in the end, be raised--gives the out party a chance to make mischief and pressure the White House. There's no question that Obama wouldn't have taken the approach he did under Bush if his had been the deciding vote.Carney said the administration wants a "clean piece of legislation" with no amendments--but John Boehner and the Republicans, having wrested $38 billion in spending cuts in the Friday night deal that averted a government shutdown, aren't likely to let that happen.The tenor of the briefing room made clear just how fundamentally the GOP has altered the terms of political debate. Carney used the phrase “deficit reduction” again and again, and promised there would be more in the economic proposals the president will unveil in a speech Wedesnday at George Washington University. The spokesman fielded just one question (from April Ryan of National Urban Radio) about the human toll of the spending cuts contained in the eleventh-hour deal, which has infuriated the left. (“What have they done with President Obama? What happened to the inspirational figure his supporters thought they elected?” Paul Krugman asks in the New York Times.)Instead, Carney insisted that Obama would show his “seriousness” about shrinking the deficit—underscoring how the president is now playing on Republican turf, in which cutting spending (and taxes) is the holy grail.