Former Pennsylvania Sen. Rick Santorum is running for president again, but with a retooled message and hopes of appealing beyond his socially conservative base. (Eric Gay/AP)

Rick Santorum won primaries and caucuses in 11 states in 2012, coming in a respectable second in the GOP presidential primary season. And Republicans have a history of bestowing their nomination on the next guy in line, usually an also-ran from the last contest.

Yet the former senator from Pennsylvania is rarely mentioned in the already feverish pre-game 2016 chatter among the political commentariat and the donor class.

That’s just the way he likes it. Or so he says.

“America loves an underdog. We’re definitely the underdog in this race,” he said in an interview Tuesday. Santorum added that being underestimated — again — “has given me a lot of latitude.”

His iconic sweater vests will likely make a return appearance. But Santorum 2.0 will be a very different presidential campaign than the one that came from almost nowhere to win the Iowa caucuses in an overtime decision, he vows.

“I get the game,” Santorum said.

Where he had to build his operation from the ground up in 2012, Santorum now has a grass-roots operation called Patriot Voices, which boasts 150,000 activists across the country. Its current push, an online petition drive to oppose President Obama’s recent executive action on immigration, has generated what Santorum strategist John Brabender says are “30,000 new e-mail relationships.”

Whether Santorum can raise the money he needs is another question. Foster Friess, the benefactor who ponied up $2.1 million to a pro-Santorum super PAC in 2012, says he would support him again. The former senator is sounding out other deep-pocketed donors, whom he declined to identify.

He is retooling his message, hoping to appeal beyond his socially conservative base and reach blue-collar voters who are being left behind in the economy.

“I don’t think I’ve met a ‘suit’ yet,” Santorum said of his travels around the country. “It’s very much heart of America, average Americans who have found a place where they see someone who will stand up and fight for them. If the Republican Party has a future — and I sometimes question if it does — it’s in middle America. It’s not in corporate America.”

That is a theme he has sounded for years, though it often got overlooked in the 2012 campaign, where most of the attention was on Santorum’s culture warrior credentials.

“Part of what I had to do last time was lay out my bona fides” on moral and social issues, Santorum said. “That’s done.”

At the same time, Santorum is likely to have more competition for the support of social conservatives than he did in the last campaign. Former Arkansas governor Mike Huckabee, who won the Iowa caucuses in 2008 and retains a strong reservoir of support among evangelical voters, is considering another White House bid.

Santorum argues that the reemergence of immigration as an issue will work in his favor because he takes a tougher line than many other Republicans do.

“I take the approach that immigration policy in America ought to be about Americans,” he said. “The principal focus of immigration policy is not about the rest of the world. It’s about us.”

The former senator hopes to revive his profile in the coming months with a series of trips to the early-contest states of Iowa, South Carolina and New Hampshire.

Santorum and his wife, Karen, have also written a book, due out in February, about their family’s experiences since the birth of their daughter Bella, who has a rare, usually deadly genetic condition called Trisomy 18.

Reflecting on how a presidential campaign could be different this time around, Santorum said: “We’re just obviously in a better place right now. Our message will be a lot more focused this time than it was last time.”

Santorum is running again. The question is whether, as the race heads to new terrain, he’ll still be able to keep the pace.