Lashing out on two fronts, Rick Santorum on Saturday questioned President Barack Obama's Christian values and attacked GOP rival Mitt Romney's Olympics leadership as he courted tea party activists and evangelical voters in Ohio, "ground zero" in the 2012 nomination fight.

Santorum, a former Pennsylvania senator known for his social conservative views, said Obama's agenda is based on "some phony theology. Not a theology based on the Bible. A different theology." He later suggested that the president practices a different kind of Christianity.

"In the Christian church there are a lot of different stripes of Christianity," he said. "If the president says he's a Christian, he's a Christian."

The Obama campaign said the comments represent "the latest low in a Republican primary campaign that has been fueled by distortions, ugliness, and searing pessimism and negativity."

Santorum was forced on his heels in recent days after a top supporter suggested women use aspirin to prevent pregnancy.

In Ohio, a Super Tuesday prize, he shifted decidedly to offense before friendly crowds. Trailing Romney in money and campaign resources, Santorum is depending on the tea party movement and religious groups to deliver a victory March 6 in the Midwestern contest.

More delegates will be awarded in Ohio than in any other state except Georgia in the opening months of the Republican campaign. Ohio and Georgia are two of the 10 contests scheduled for March 6, a benchmark for the primary campaign that often decides who can continue to the next level.

Santorum has surged in recent opinion polls after capturing Republican caucuses in Minnesota and Colorado and a non-binding primary in Missouri on Feb. 7. Several polls have shown him ahead in Romney's native state of Michigan, where primary voters cast ballots a week from Tuesday.

Obama's campaign team has responded by starting to consider the possibility that Santorum rather than Romney could be the Republican nominee. The Chicago-based organization has begun scrutinizing Santorum's past record and asked its Pennsylvania allies to look for information that might be used against Santorum in future ads and speeches.

Even as he criticized Obama, Santorum also went after one of Romney's most promoted achievements — his leadership at the 2002 Winter Olympics in Salt Lake City.

"One of Mitt Romney's greatest accomplishments, one of the things he talks about most is how he heroically showed up on the scene and bailed out and resolved the problems of the Salt Lake City Olympic Games," Santorum said. "He heroically bailed out the Salt Lake City Olympic Games by heroically going to Congress and asking them for tens of millions of dollars to bail out the Salt Lake games — in an earmark, in an earmark for the Salt Lake Olympic games."

The Romney campaign does not dispute that congressional earmarks helped save the games. But they noted that Santorum voted for those earmarks, among many others, when he was a senator.

"Sometimes when you shoot from the hip, you end up shooting yourself in the foot," Romney spokeswoman Andrea Saul said. "There is a pretty wide gulf between seeking money for post-9/11 security at the Olympics and seeking earmarks for polar bear exhibits at the Pittsburgh Zoo."

Santorum used a later appearance before the Ohio Christian Alliance to go after Romney for using his financial advantage as "as a club to beat anyone who gets in his way." But he saved his most pointed criticism for Obama, suggesting that the Democratic president's health care overhaul encouraged abortions by requiring insurance plans to cover prenatal screenings.

"It saves money in health care. Why? Because free pre-natal testing ends up in more abortions and therefore less care that has to be done because we cull the ranks of the disabled from our society," Santorum said. "That too is part of ObamaCare. Another hidden message as to what Obama thinks of those who are less able than the elites who want to govern our country."

Santorum planned to finish his day in Akron before heading to Georgia on Sunday. While 63 delegates are at stake in Ohio, Georgia offers 76.

"There's no state that can shout louder. You are the biggest state. You've got the biggest trove of delegates," Santorum told the Brown County Republican Party on Friday night. "This is ground zero. Ohio."

Questions about whether Santorum can sustain his rise in the polls come amid signs of stress within his campaign, mainly disorganization. Romney's machine, coupled with new scrutiny for Santorum's view of social issues as well as governmental policies, will give Santorum little margin for error.

As an example, one misstep by a Santorum supporter kept the former senator off message at times for two days.

Foster Friess, the main donor behind Santorum's "super PAC," created a stir Thursday when he related on MSNBC an old joke about how aspirin used to be a method for birth control. "Back in my days, they used Bayer aspirin for contraception," Friess said with a grin. "The gals put it between their knees and it wasn't that costly."

Friess apologized Friday in a blog post. But Santorum was repeatedly forced to distance himself from his surrogate's comments, which Santorum described as "a bad joke." The comments drew unwanted attention to Santorum's own musings about contraception and women's issues.

"Santorum has been in the position of explaining on all of these issues. And when you're explaining in politics, you're losing," said Phil Musser, a GOP strategist who doesn't work for either campaign.