The sudden barometric change in Washington has arrived so rapidly that it is hard to comprehend. “The town is turning on President Obama,” announced Politico honchos and custodians of the conventional wisdom Mike Allen and Jim VandeHei, and they’re right. Republicans are gleefully unleashing a vast investigative apparatus; erstwhile supporters like Jon Stewart are mortified. The black clouds may dissipate within a few days or weeks, or they may hover over the White House for the rest of Obama’s term. In the meantime, it is dizzying enough that, even in such a short period of time, we ought to step back and ask, what the hell just happened here?