Democratic primary voters need to pay close attention to independents. The polls suggest hard-core Democrats would be happy either with Hillary Clinton or Mr Obama. But there is no doubt who does better with independents. Until this week, Mrs Clinton's strength has been her ability to turn out the vote in solid Democratic states such as California and solid Democratic constituencies such as blue-collar voters. But she repels many independents who associate her with Beltway business-as-usual.
In contrast, Mr Obama sounds the themes that most appeal to independents—frustration with America's broken politics; hope of finding pragmatic solutions by reaching across the partisan divide. And independents have not disappointed him. Mr Obama beat Mrs Clinton among such voters almost everywhere, even in her strongest states such as New York and California. A recent Pew poll suggests Mr Obama has a 62% approval rating among independents, the highest of any candidate.
This should weigh heavily on the minds of the Democratic “superdelegates” (office holders and party elders who have an ex officio vote in the convention) if they are called upon to break a tie in the delegate race. Mrs Clinton's biggest problem is not that she is being out-campaigned by the silver-tongued Mr Obama. It is that she seems to belong to the previous era of American politics—the one of battling political machines. Republicans have accidentally stumbled through to the next age of politics, although the message has not yet reached the backwoods wing of the party. The big question now for many Democrats is whether their party can do likewise.