The DNC mercilessly pummels Mitt:

It's the kind of ad a Republican would gleefully use against a Democrat. But J.P. Green questions the timing:

I gather the strategy behind the ad is that Mitt Romney is the GOP's most formidable opponent for President Obama, and weakening him now could help one of the more vulnerable Republican candidates get the GOP nod, thereby improving Obama's reelection prospects. The strategy is a bit risky in any case. The GOP has other candidates who are electable in a declining economy, despite the clown show of recent months.

A shorter, punchier, funnier version of the ad – now running in five states and DC – can be seen below: