Good news just keeps coming for former Pennsylvania senator Rick Santorum. Not only does a new Rasmussen poll show him leading Romney by 12 points nationally, but a new poll from the American Research Group shows that he’s also made a significant jump in the state of Arizona:

The American Research Group survey shows Romney with 38% support among likely Republican primary voters, followed by Santorum at 31%, Newt Gingrich at 15% and Ron Paul with 11%.

The new figures represent a significant shift since January, when a similar poll indicated Romney and Gingrich tied at 32%, Paul with 12% and Santorum with 10%.

That earlier ARG poll wasn’t the only poll that, just a few weeks ago, showed Santorum noticeably behind in the Grand Canyon State. A Feb. 1 poll from Rasmussen suggested the state would be a lock for Romney, who then led Gingrich 48 percent to 24 percent. At the time, Santorum drew just 13 percent support.

Santorum’s surge in Arizona is all the more remarkable because he’s paid very little attention to the state. While Romney has hit the Southwest, Santorum has focused the majority of his energy on Michigan and Ohio, where his efforts are paying off in the polls. A second-place finish in Arizona would bolster Santorum’s case that he’s the clear not-Romney in the race, but it wouldn’t do much to augment his delegate count. Arizona is a winner-take-all primary. Indeed, Ben Shapiro reports that most of the states that favor Santorum are proportional, whereas Romney will likely fare well in the winner-take-all contests. That makes the math difficult for Santorum. Still, it can’t hurt him to finish second in every state in which he doesn’t finish first. If he shows himself to be strong across the country, anything could happen.