COULD FORMER U.S. Sen. Rick Santorum's chances to win his home state's presidential primary election be slipping away?

Santorum holds a razor-thin 2-percentage-point lead over former Massachusetts Gov. Mitt Romney in Pennsylvania's April 24 Republican primary, according to a Daily News/Franklin & Marshall College Poll to be released Wednesday.

Romney, who took 28 percent to Santorum's 30 percent, has room to grow since 24 percent of the 505 registered Republicans in the poll said that they are undecided.

With four weeks until Republicans cast their ballots here, Santorum's home-state strength has been sapped from the commanding 29-percentage-point lead he held on Romney in February's Franklin & Marshall poll.

And Romney, who has a financial advantage in campaign cash, has yet to air TV commercials in this state.

Could April 24 be the end of the road for Santorum's campaign?

"If he wins it narrowly, he loses it," poll director G. Terry Madonna said of Santorum. "A close election here is devastating."

What happened?

Those polled overwhelmingly listed the economy as their main concern. But Santorum's campaign has been sidetracked for weeks at times by social issues.

Madonna said that Santorum boxed himself in by turning to social issues, wasting a chance to expand his base in states such as Pennsylvania with "complex and diverse" electorates that include many moderate voters.

"When we ask people what they care about, the social issues don't even register," Madonna said.

From February to March, the poll found a 10 percent decrease in the number of people who consider a "strong moral character" to matter most in a Republican presidential nominee, corresponding to a 7 percent increase among Republican voters who said that the ability to defeat President Obama matters most.

Romney defeated Santorum by a mere 3 percent in the Feb. 28 Michigan primary.

But that state, where Romney's father served as governor from 1963 to 1969, allows all voters to cast ballots in primaries. Santorum campaigned there for support from Democrats, which Romney called a "dirty trick."

Former U.S. House Speaker Newt Gingrich and U.S. Rep. Ron Paul, of Texas, trail in single digits in the poll. Gingrich is at 6 percent while Paul is at 9 percent.

"They are clearly going nowhere in this race," Madonna said of Gingrich and Paul. "This is clearly a two-person race."

Santorum was seeking a third six-year Senate term when Bob Casey Jr. trounced him by 17 percentage points in the 2006 general election.

The poll also shows that the vast majority of registered Republicans - 81 percent - don't know much about the five men who now seek to prevent Casey from winning a second Senate term.

Malvern venture capitalist Steve Welch, the state Republican Party's endorsed candidate, took just 1 percent, the same as former Santorum staffer Marc Scaringi and Bucks County businessman David Christian.

Armstrong County coal company owner Tom Smith, who was first to broadcast campaign commercials on cable television, led the field with 9 percent while former state Rep. Sam Rohrer, of Berks County, a 2010 candidate for governor, had 7 percent.

"We've never seen a Senate race without at least one major player," said Madonna. "Who are they? Nobody knows."