As Rick Santorum has shifted his sights from securing the GOP nomination outright before Tampa to merely blocking Mitt Romney, the pro-Santorum Super PAC Red, White and Blue Fund has correspondingly gone progressively negative in its ads. Where once the PAC sought to sell Santorum, it now seeks to undermine Mitt Romney. As far as strategy goes, it’s about the only one that makes sense. Romney’s negativity toward Newt Gingrich in both Iowa and Florida certainly weakened the former Speaker. Who’s to say the Red, White and Blue Fund won’t significantly weaken Romney with ads like this one, which airs in Wisconsin? Click the image to watch.

Again, Rick Santorum, Ron Paul and Newt Gingrich collectively needed to win 55 percent of all the delegates up for grabs after March 14. Between then and now, they’ve collected about 23 percent. Next Tuesday, 96 delegates are up for grabs in D.C., Maryland and Wisconsin. Santorum isn’t even on the ballot in D.C. and he trails Romney by 13 points in Wisconsin, which is winner-take-all by district and statewide. Romney is also expected to win Maryland.

Santorum has kinda, sorta hinted that Wisconsin could be the end of the line for him, but he has also signaled he intends to go all the way to Tampa. As his fighting words to New York Times reporter Jeff Zeleny yesterday indicated, he’s still got a few tricks up his sleeve. This week’s respite from primary on top of primary — especially in conjunction with the Obamacare hearings — might just give Wisconsin voters the space they need to reassess Rick Santorum and deliver an unexpected win for him.