In many ways, the 2012 presidential election looks a lot like the one in 2004. A divisive incumbent in a polarized electorate faces a surprisingly strong challenge from a lackluster politician against the backdrop of a stagnant economy. Like John Kerry, Mitt Romney is a Massachusetts-based candidate with a reputation for serial inconsistency, who lacks the full-throated support of his party's base. And like George W. Bush, Barack Obama is running a campaign that highlights his strengths as a leader and portrays his opponent as untrustworthy and unprincipled. To wit, here is what Obama said in an interview with an NBC affiliate in Ohio:
"Mr. Romney was one of the biggest promoters of the individual mandate. In Massachusetts, his whole idea was that we shouldn't have people who can afford to get health insurance to not buy it and then force you or me, or John Q. Public to have to pay for him when he gets sick. That's irresponsible. That's exactly what's included as part of my health care plan. And the fact that a whole bunch of Republicans in Washington suddenly said, this is a tax – for six years he said it wasn't, and now he has suddenly reversed himself.
"So the question becomes, are you doing that because of politics? Are you abandoning a principle that you fought for, for six years simply because you're getting pressure for two days from Rush Limbaugh or some critics in Washington? One of the things that you learn as President is that what you say matters and your principles matter. And sometimes, you've got to fight for things that you believe in and you can't just switch on a dime."" [Emphasis added]
This is a variation on the "flip-flopper" charge that Bush used to attack Kerry in the 2004 election. Unfortunately for the Obama team, there's not much evidence for the effectiveness of the attack; Kerry did a decent job of winning voters who approved of Bush's performance, and overall, outperformed the models for the 2004 election.
That said, because both conservatives and liberals see Romney as opportunistic and untrustworthy, there's a chance that the attack will have more currency. Regardless, you should expect to see the Obama team devote more time to attacking Romney as a man without principles as the campaign progresses and the economy drops away as something the president can run on.