"The assumption should be, coming into Pennsylvania, he will be up in the polls, even though he was drummed out of here pretty hard-core in 2006," said Villanova University political scientist Lara Brown. She added that Santorum is benefiting from national attention and the fact that most Pennsylvanians are not yet paying close attention to the race.
Incidentally, Pennsylvania has also been home to two of the other GOP contenders: former House Speaker Newt Gingrich, a Harrisburg area native; and Texas Rep. Ron Paul, who grew up in suburban Pittsburgh.
One problem for all of Romney's rivals is that votes don't win the nomination; delegates do. It was the same daunting problem Hillary Clinton faced when she hit Pennsylvania four years ago. Though she won that primary over Barack Obama, experts warned correctly that the Keystone State's delegates would split, Obama would continue to gain in numbers, and Clinton had no clear path to "out-delegate" him.
Santorum faces that problem today, according to Josh Putnam, a political scientist and delegate expert at Davidson College. "Any night where Santorum doesn't cut into Romney's delegate lead, and cut into it significantly, is a win for Romney," he said.
Last week, an array of Pennsylvania Republicans endorsed Romney. "The thing is, Romney is more conservative than Santorum," said Dwight Weidman, Franklin County's GOP chairman. "Of course, that runs contrary to what the news reports, but it is true."
Santorum, who represented Pennsylvania in Congress from 1991 to 2007, began as a "progressive conservative" and ended up a social-conservative flamethrower. In between, he lost the voters whose yard signs read "Vote Gore-Santorum" in 2000.
Jim Burn, the Democrats' state chairman, predicts a close race.
"Once the national press and local press start reminding voters why they ran him out in 2006, you are going to see a tight race," he said. "The first thing we will do is remind voters of his insistence that taxpayers pay for his kids' home-schooling when he no longer maintained a legal residence here."
Burn was referring to an old controversy over whether the then-U.S. senator's family lived in Penn Hills, a Pittsburgh suburb, or Leesburg, Va. It erupted when the Penn Hills School District tried to recover more than $70,000 that it contended the state wrongly sent to a cyber charter school to educate Santorum's children. The Pennsylvania Education Department ultimately agreed to pay the district $55,000 to settle the dispute.
Villanova's Brown believes that controversy will bother tea-party conservatives, while other conservatives will struggle with Santorum's support of Arlen Specter over Pat Toomey in the 2004 Senate primary. Meanwhile, women in the Philadelphia and Pittsburgh suburbs will hate his stance on contraceptives.
"If Santorum cannot win his own state," she said, "he is not a national candidate. But if Romney wins here, he has proven he is a battleground winner" - just as he has with his victories inFlorida, Ohio, Michigan, Nevada, and New Hampshire.
Salena Zito writes for the Pittsburgh Tribune-Review.