WASHINGTON - Former Pennsylvania senator Rick Santorum is the GOP's latest presidential "flavor of the month," propelled by his party's large bloc of evangelical and socially conservative voters.

A rogues gallery of dubious candidates have received this temporary designation over the course of the GOP's increasingly bitter fight for the nomination: Rep. Michelle Bachmann, Gov. Rick Perry, and Herman Cain, who were all at the front of the pack at one time, only to fall behind and drop out of the race.

Former Speaker Newt Gingrich has had several debate-driven comebacks, with a big win in South Carolina. More recently, since his poor showing in Florida and Nevada, he has lost support. He is now in second place in the national party rankings at 21 percent to front- runner Mitt Romney, and his campaign is deeply in debt.

Enter Santorum who trounced Romney in this week's contests in Colorado, Minnesota and Missouri, though it remains to be seen whether this was a political fluke in states where voter turnout was relatively light and there were no delegates at stake in any of them.

Throughout his Senate career, Santorum was the clear, undisputed leader of the GOP's social conservative wing that has become a stronger force in the party's delegate-selection process. And he has fervently championed their issues throughout his shoe-string campaign -- i.e. the role of religious faith in the life of the nation, the government's war on right to life abortion issues and their fierce opposition to same-sex-marriage.

However, his larger political profile has remained cloudy, even though he's set forth a full blown campaign agenda of tax cut reforms and economic revival -- issues Romney has made the central focus of his candidacy.

While Santorum has had an influential track record in the Senate over two elections, 1994 and 2000, he doesn't mention he was overwhelmingly defeated for a third term, losing by a whopping 18 points, 59 percent to 41 percent, to Democrat Robert P. Casey, largely on economic issues.

For better or worse, those are the overriding issues that will likely decide the outcome of the 2012 general election and whether President Obama can win a second term.

Santorum championed many issues in the Senate, but he was not especially known for his skill or leadership on the economic issues that cost him his Senate seat in 2006.