The former Pennsylvania senator, who is leading in national polls in the race for the GOP presidential nod, is fiercely anti-abortion and believes that states have the right to ban birth control — stances that are at odds with the views of most American Jews.

Not a problem, says Matt Brooks, executive director of the Republican Jewish Coalition.

“Jobs and the economy and international affairs, these macro issues are front and center,” he said. “If the micro issues, abortion and contraceptives, become predominant, then you’ve got a problem. But this is a big picture, big issue, high-stakes election.”

But the prospect of Santorum winning the Republican nomination excites Jewish Democrats, as they believe he will be an easier opponent for President Obama in November.

Among Jewish Republicans, the bulk of the party’s Jewish donors and advisers have signed with Mitt Romney. The former Massachusetts governor’s relative moderation was seen as a natural fit for a GOP Jewish constituency that is hawkish on Israel and often fiscally conservative but averse to extremes on social issues.

“We know he’s a great friend of Israel,” Fred Zeidman, a Houston lawyer who is one of Romney’s leading fundraisers, said of Santorum. “I do fear his social views will be anathema to a great deal of our Jewish community.”

Romney Republicans like Zeidman have counted on Romney’s moderation to carry swing states where substantial Jewish populations could make a difference — for instance, in Florida, Pennsylvania and Nevada.

In recent interviews, several top Jewish Democratic activists have launched conversations, unsolicited, with a reporter with “What about Rick Santorum?” followed by hearty, relieved laughter.

“He will clearly be a nonstarter with the Jewish community,” said David Harris, president of the National Jewish Democratic Council. “I wish him the best of luck in the primaries.”

Such blasts are bound to increase now that Santorum is leading in polls for the Feb. 28 Michigan primary. Winning in Michigan would likely cripple the campaign of Romney, who until now (although with some difficulty) had claimed front-runner status: It is the state in which Romney grew up and where his father had been a popular governor. Arizona also votes the same day; polls show Romney in the lead there.

Liberal websites have compiled “greatest of” lists of Santorum’s hard-line stances on social issues.

“During his 99-county tour of Iowa, Santorum frequently compared same-sex relationships to inanimate objects like trees, basketballs, beer, and paper towels,” Think Progress said Jan. 4 after Santorum’s first surprise showing — a virtual tie with Romney in the state’s caucuses.

Lonny Kaplan, a New Jersey businessman who is leading Santorum’s fundraising in the Jewish community, says his candidate can overcome his Jewish problem by making his election about the economy and backing Israel as its tensions with Iran increase.

“My sense is that those issues, while they’re important to him, are not what his campaign is about,” Kaplan said. “Obviously it’s a challenge. It doesn’t hurt him during primaries. In the general [election] they’ll raise it again and again, so he counters it by saying what his rationale is for running.”

There is a precedent: Ronald Reagan campaigned well to the right of his GOP rivals and predecessors, yet won nearly 40 percent of the Jewish vote in 1980. It was a year, like this one, when the U.S. was tangling with a recalcitrant, unpredictable Iran and a sagging economy. That’s a bigger chunk of the Jewish vote than any Republican had won in decades. No Republican presidential candidate since has matched that level of Jewish support.

Kaplan says 2012 is similar, given the jobs crisis and the tensions with Iran. Santorum has been the most hawkish of the candidates on Iran, going beyond years of “no options are off the table” language to explicitly say that he would order a U.S. strike if necessary to keep Iran from having a nuclear weapon.

“Israel is severely challenged today, and all of us are very comfortable with Rick’s stand on Israel,” said Kaplan, a former president of the American Israel Public Affairs Committee. “And while the economy is showing signs of improvement, it’s been bad for four years.”

Harris of the NJDC said that was wishful thinking, dismissing any efforts to compare Santorum to Reagan or to George W. Bush. While those candidates embraced socially conservative stances, Santorum has been defined by them, he said.

“It’s not that he takes a principled stand re: abortion,” he said. “It’s that he’s long prided himself on being the most far-right social issues candidate.”

Alan Steinberg, a New Jersey political commentator who has been advocating for a more conservative alternative to Romney, suggested that whatever support Santorum would lose among more moderate Jews he would make up in support among Jewish conservatives.

“His stance on social issues will be a plus, particularly in the Orthodox community,” he said. “He will have the Orthodox,  Jewish conservatives and the pro-Israel community that is pro-Netanyahu and pro-Likud.”