by Maisie Allison

The Romney campaign goes for it in Santorum's home state with a massive ad buy ("We fired him as senator, why promote him to president?"): 

Alex Burns captions

It's a negative hit as personal and locally-tailored as the positive sales pitch Santorum's delivering to voters ("You know me") and it's the kind of thing that could either demoralize the former Pennsylvania senator, or infuriate him enough to keep the next two weeks as ugly as ever.

Ed Morrissey adds

Since Romney should have little trouble winning in the other four states that go to the polls on the 24th — New York, Connecticut, Rhode Island, and Delaware, the latter of which is a winner-take-all primary — he can spend almost all of his time stumping in Pennsylvania.  That makes the fight uncomfortably similar to Michigan and Wisconsin, both of which Santorum was perceived as having a lead or an edge, and both of which fell to Romney in the end. … Unfortunately for Santorum, failure in Pennsylvania might spell the end of not just the current political campaign, but any future in electoral politics.  

The Romney camp is suspending the attack ad while Santorum attends to his ailing daughter, Bella. Meanwhile, the Obama campaign runs against big oil: 

And the RNC paints the president as a desperate politician: 

Total Super PAC spending now exceeds $86 million. 

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