A paranoid and sinister spot from the Romney campaign:

Sam Stein captions:

The clip insinuates that Obama's reelection campaign put large sums of money behind anti-Romney efforts. (While affiliated groups did, the Obama campaign was not involved.) It also plays up the now infamous line from an anonymous "Democratic strategist aligned with the White House" that they'd have to pursue a "kill Romney" strategy unless the economy improved. … There's no mention of former Sen. Rick Santorum, Romney's chief Republican rival, in the spot.

The second [reason the ad is telling] is the overt plea for cash. In both the text below the video on the Romney campaign's landing page and in ads that pop up while it plays, the campaign solicits donations. Having asked supporters to visit his website and help the campaign in any capacity during his victory speech last night, it's becoming more and more evident that Romney is strapped for cash.

Shifting tones dramatically, Romney ridicules the "Democrats for Santorum!" phenomenon in Michigan: 

Ron Paul has reissued the following ad from January, perhaps in an effort to quiet speculation that he's cut some sort of deal with the Romney camp:

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