WASHINGTON – A devastating new ad from 2012 Republican frontrunner Mitt Romney quotes President Barack Obama's early promise that he "will be held accountable" for the economy and face a "one-term proposition" if it fails to improve.

Amidst an ominous backdrop of dire economic news including rising foreclosures and misery index, the ad quotes Obama from a February 2, 2009 interview shortly after assuming office.

"A year from now, I think people are going to see that we're starting to make some progress," Obama says. "If I don't have this done in three years, then there's going to be a one-term proposition."

Romney's ad is a sign that the faltering economy could be a key determinant of Obama's reelection hopes. Although Obama bears limited blame for the sluggish pace of the recovery, presidents' second-term aspirations traditionally rise and fall on economic conditions.

The spot, which is now Romney's second anti-Obama ad in two weeks, also suggests that the former Massachusetts governor is squarely focused on the general election. He hasn't attacked any of his GOP competitors, who he'll have to defeat in the primaries that begin next January.

Romney and the 2012 field have yet to persuade the public on their plans for the economy. The ex-governor's own economic vulnerabilities could also be a factor in the election: as CEO of Bain Capital, he oversaw the layoffs of thousands of workers.

Scroll down to watch the ad, via Romney's YouTube account.

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