Former U.S. Sen. Rick Santorum has surged to a 29-point lead over the other three Republican presidential hopefuls in Pennsylvania, a state he represented for more than a decade, a new poll shows.

And he has narrowed the gap between himself and President Barack Obama in a hypothetical head-to-head matchup among all registered voters in the state, which hasn't sided with a Republican nominee in nearly 25 years.

The findings, from a new statewide Franklin & Marshall College poll, reflect Santorum's growing support, particularly among tea party and evangelical voters, following a popular-vote sweep of three states earlier this month.

"Santorum had something the other candidates didn't, and that is a niche with social conservatives," said G. Terry Madonna, the poll director and head of F&M's Center for Politics and Public Affairs. "Even though the election was all about the economy, he continued to bring up the social issues, and that allowed him to have a core of support."

The poll shows Santorum leading his nearest rival, former Massachusetts Gov. Mitt Romney, 45 percent to 16 percent among Republican voters here. Many observers presumed Romney would be a shoo-in for the nomination, at least until Santorum won the popular votes in Colorado, Minnesota and Missouri.

Newt Gingrich, a former House speaker whose campaign is being led by former Congressman Bob Walker of Manheim Township, is getting support from 9 percent of voters and U.S. Rep. Ron Paul is getting 7 percent. Twenty-two percent of Republicans are still undecided, and 1 percent indicated support for another candidate.

The survey of 278 Republican voters between Feb. 14 and Monday has a margin of error of 5.9 percentage points.

In a head-to-head matchup with the president, Santorum fares best among the field of Republicans with all 592 registered voters polled. Obama leads him 41 percent to 37 percent, within the poll's margin of error.

In January, Obama was beating Santorum by 13 percentage points, 43 percent to 30 percent.

The four-way race for the Republican presidential nomination is expected to extend beyond primaries in Arizona and Michigan, which vote Tuesday, and Super Tuesday on March 6, perhaps making Pennsylvania's April 24 primary relevant for the first time in years.

"Santorum's big lead here doesn't mean that he's an automatic winner here," Madonna said. "Forty-five percent of voters said they could still change their minds."

Gerald Mitterer, 70, of Willow Street, is among the undecided voters at this point, but he says he is leaning toward Santorum.

"I like his philosophies. I like his conservative stance. I like his record, even though he's been badmouthed by Democrats," said Mitterer, a self-employed insurance salesman.

He said he would not consider voting for Paul because he believes some of the candidate's ideas are too extreme, such as his idea to close American military bases around the world.

"I cannot support that," Mitterer said. "That's just a bad idea. You cannot disengage yourself from all the things that can go on across the world."

James Garland, 56, of Lititz, voted for Paul in the 2008 primary but said he's undecided this year. If anything, he's leaning toward either Romney because of his professional background or Santorum because of his conservatism and roots in this state.

"I like the fact that Romney was a businessman," said Garland, who owns Reflections restaurant in Manheim Township. "But, at the same time, I don't like the fact that he's almost like a Democrat in Republican clothes."

He said he won't vote for Paul again because he doesn't believe he has a chance to win the nomination.

"I want somebody who's going to take care of the deficit and make some of the hard choices, even if it means cutting some of the entitlements," Garland said. "I like Ron Paul. He makes a lot of sense. But I don't think he's got a chance of being elected."

David Hollinger, who has been a supporter of Santorum's since his first run for Senate, said Santorum's stance on social issues often overshadows his knowledge of other pressing issues.

"The news talks about the social issues, but he's also speaking out as much on the economic issues of the day and national security issues of the day," said Hollinger, the chairman of Four Seasons Produce.

Santorum served in the U.S. Senate from 1995 through 2006, when he lost re-election in a landslide to Democrat Bob Casey Jr. Casey, the son of a popular former governor here, beat Santorum by 18 percentage points and more than 708,000 votes in the state.

Hollinger credits Santorum's rising popularity to the candidate's diligence and tenacious work on the campaign trail, as well as his steadfast conservatism and status as the choice of the grass roots, not the establishment.

"Rick Santorum, you could say, has not been chosen by the Republican elite," Hollinger said. "He didn't get to the top to be blessed. He truly would be the grass-roots nominee."

READ: Summary of findings of Franklin & Marshall College poll (PDF)

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