Former U.S. President George W. Bush, left, and U.S. President...

Former U.S. President George W. Bush, left, and U.S. President Barack Obama arrive in the East Room for the unveiling of Bush's official portrait at the White House. (May 31, 2012) Credit: Getty Images

The federal report on the cratering of middle-class wealth from 2007 to 2010 is a reminder of how unusual this presidential campaign is, something that has gotten largely lost in the daily back-and-forth.

It's rare for a new president to take office during a recession, and rarer still for one to take office amid a horrific crisis, as Barack Obama did. Bill Clinton, Ronald Reagan and Jimmy Carter took office soon after recessions had technically ended.

But Obama was inaugurated right at the deepest point of the downturn; this was a far deeper recession than any of those others; and the Obama recovery, though real, is a lot less impressive than most comparable periods after recessions.

Which means: Obama's chances for reelection depend heavily on whether the American people hold Obama or George W. Bush responsible for the economy. In effect, this election is a matchup between Obama and his predecessor in a way we haven't seen in previous elections.

This also means there will be much uncertainty about how economic "fundamentals" play out. One political scientist has found that the first year's economic performance works backward from what is typical, with a worse economy in Year 1 helping reelection. If true, Obama is likely to win again this year . . . but there's no way to be sure it is true.

That's why so many of the campaign messages this year come down to the argument about whether Obama should be rewarded or punished for the state of the economy, which largely boils down to that question of Obama vs. Bush.

In some ways, that's frustrating. Many analysts might logically point out that what voters should be comparing are the plans that Obama and Mitt Romney have for the future. And perhaps voters should do that. But it's unlikely they will. Swing voters, especially, tend to be politically indifferent and inattentive, so they're not likely to know what the candidates plan to do if elected, and are even less likely to try to evaluate those plans.

All this means you can expect more skirmishes over the candidates' platforms, and perhaps even some serious debate about issues such as whether state and local governments should be spending more or less. But the overriding imperative for the Obama campaign has to be to push voters to see the current economy, weak as it is, as much better than the one he inherited from Bush.

Meanwhile, the overriding imperative for Team Romney has to be to induce as much amnesia as they can about how -- and when -- all this trouble started. Expect that to be a key battleground as the campaign goes on.

Jonathan Bernstein is a political scientist who contributes to the Washington Post blogs Plum Line and PostPartisan.

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