COLUMBUS, Ohio — White House candidate 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 policies, said that Obama’s agenda is “not about you. It’s not about your quality of life. It’s not about your jobs. It’s about some phony ideal. Some phony theology. Not a theology based on the Bible. A different theology.”

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 Ohio, one of Super Tuesday’s biggest prizes.

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.

Even as he criticized Obama, Santorum also went after one of Romney’s most promoted achievements — his leadership at the 2002 Olympic Winter Games 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.”

Following the tea party rally, Santorum headed to a luncheon with the Ohio Christian Alliance and will finish his day at a Lincoln Day dinner in Akron.

“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.”

While 63 delegates are at stake in Ohio, Georgia offers 76.

Hours earlier, the former Pennsylvania senator stood at the State House in Columbus as state Attorney General Mike DeWine formally shifted his allegiance to Santorum from rival Mitt Romney, another sign that Santorum has seized the momentum in the roller coaster Republican presidential contest.

His socially conservative message has captivated crowds this week from Boise, Idaho, to Romney’s hometown of Detroit to the southern Ohio village of Georgetown.

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 said that he wouldn’t try to take away the birth control pill or condoms but that states should be free to ban them. He told a Christian blog last year that as president he would warn the nation about “the dangers of contraception” and the permissive culture spit encourages. He’s also questioned whether women should be in combat and said that “radical feminists” have undermined the traditional family by “convincing women that professional accomplishments are the key to happiness.”

The contraception flap, according to Republican observers, is evidence of an undisciplined campaign that is already stumbling under the weight of intensifying scrutiny. Polling suggests that significant numbers of voters still don’t know Santorum well. He may struggle to win over female voters in particular as they begin to pay more attention, according to Phil Musser, a GOP strategist who doesn’t work for either campaign.