By all usual metrics, Rick Santorum should be well positioned to compete for the Republican presidential nomination in 2016. Yet as the former Pennsylvania senator and 2012 runner-up announced his candidacy last week, his chances seem remote.

It would be a mistake to write him off. When the last election cycle begin, Santorum was an unknown candidate with a Google problem. He went on to win 11 primaries and caucuses.

Former U.S. Senator Rick Santorum (R-PA) announcing his candidacy for the 2016 Republican presidential nomination May 27, 2015 in Cabot, PA. Photo: AARON JOSEFCZYK,  REUTERS

Former U.S. Senator Rick Santorum (R-PA) announcing his candidacy for the 2016 Republican presidential nomination May 27, 2015 in Cabot, PA. Photo: AARON JOSEFCZYK,  REUTERS

Throughout 2011, Santorum struggled to gain traction. A series of other conservatives catapulted ahead in the polls, only to fade from the race amid gaffes (Rick Perry), scandals (Herman Cain), and general cluelessness (Michele Bachmann). Backed by billionaire financier Foster Freiss, Santorum held his own in debates and built a robust organization in Iowa.

After Santorum’s surprise win in the Iowa caucuses, a group of religious right leaders convened at a Texas activist's ranch to consolidate their support behind one candidate in hopes that social conservatives' unity could thwart the allegedly moderate Mitt Romney in his path to the nomination.

Santorum received the religious right's nod over Newt Gingrich and Perry. But Gingrich won the South Carolina primary and Romney secured the nomination.

If history is any guide, Santorum should expect significant support this time around. As he is fond of pointing out, every GOP nominee meets one of three tests. "One, they were vice president. Two, they were the son of a former president. And three, they came in second place the last time and ran again and won." 

Yet Santorum has a different image and appeal than past nominees who received the nod on their second attempt. He was a grassroots favorite, whereas Mitt Romney, John McCain, and Bob Dole were establishment figures.

Santorum has not held elected office since he lost his bid for a third Senate term in 2006. But he has won twice as many statewide elections as Mitt Romney. Santorum also has three times as much Senate experience as Marco Rubio and Rand Paul (not to mention Barack Obama), and six times more experience than Ted Cruz. Sure, Santorum's foreign policy qualifications are thin, but that hardly hurts him in a field filled with national security novices.

Santorum may have spent the past 8 years as a politician without an office, but he has continually honed his message. His 2014 book, Blue Collar Conservatives, chides the GOP for doing so little to help working people. Against conservative orthodoxy, Santorum now supports a small increase in the minimum wage. He peppers his speeches with rhetoric about how Republicans sound like all they care about is giving rich people a tax cut. (Though there is plenty of doubt about whether Santorum’s policies would actually help struggling families.)

His belief that marriage is between a man and a woman is well known. While frontrunners Jeb Bush and Scott Walker have faced questions about their social conservative bona fides, Santorum's are impeccable. His new economic populism, however modest, sets him apart from his rivals. The rest of his appeal has plenty of red meat for the anti-abortion, anti-Obamacare, and anti-immigrant factions of the party.

A devout Catholic and father of seven, Santorum and his family often attend Latin Mass at their Northern Virginia parish. Santorum agrees with the Church on abortion and marriage. But like any good Republican, he opposes Pope Francis on a wide range of non-sex-related issues. Santorum’s populist economic rhetoric may make him the least bad of the bad Catholics in the race.

In a field crowded with polished candidates in addition to the presidential-campaign-as-FOX-News-audition tier, the GOP seems content to pass on Santorum.

Yet a party the public thinks cares mostly about rich people’s interests should think twice before ignoring the only candidate with a populist economic agenda.

In 2012, Rick Santorum had to wait for other candidates to falter in order to make his rise. He may not be so lucky this time. But with Foster Friess’s millions and an unshakeable belief in his message, Santorum may stay in the race long enough to be a factor once again.