Republican presidential hopeful Rick Santorum isn't afraid to use political rhetoric to convey his apparent moral certainty on almost any subject he addresses.

Over the weekend, the conservative Catholic seemed to question the legitimacy of Barack Obama's Christian faith when he said the president's beliefs were based on some phony ideal, some phony theology.

Appearing on CBS's Face the Nation on Sunday, Santorum took a step back, insisting he had been referring to the stance on global warming that Obama allegedly shares with radical environmentalists.

I accept the fact the president's a Christian, the former Pennsylvania senator conceded, before adding that he was originally commenting about Obama's view that greenhouse gas emissions contribute to global warming.

Faith has been at the center of Santorum's presidential campaign, the linchpin of a socially conservative platform that's generally in line with the hard-right agenda of the current Republican Party.

This isn't the first time Santorum has attacked a rival, political or otherwise, over perceived theological shortcomings.

In a 2008 commencement speech Santorum gave at Ave Maria University in Florida -- an institution that describes itself as a Catholic university according to the guidelines of the Code of Canon Law -- Santorum effectively insulted a good portion of his party when he implied that mainline Protestants are no longer true Christians.

Santorum's speech, which was recently reposted by Right Wing Watch, focuses on how major American institutions are under a systematic attack by Satan -- also known as a liberal agenda. Universities, the nation's political system and even Protestant churches are all under siege, according to Santorum.

This was a Protestant country and the Protestant ethic, mainstream, mainline Protestantism -- and of course we look at the shape of mainline Protestantism in this country and it is a shambles, it is gone from the world of Christianity as I see it, Santorum said. So they attacked mainline Protestantism, they attacked the church, and what better way to go after smart people who also believe they're pious to use both vanity and pride to also go after the church?

He went on to say that the corruption of the church by Satan has led to the destruction of academia, as well as popular culture. Santorum said the erosion of decency is on display in nonpartisan events such as NBA basketball games and rock concerts.

Santorum's zeal may have played well at Ave Maria University, but railing against mainline Protestants certainly cannot be a viable way to attract a good portion of GOP voters. In fact, some could say Santorum was actually insulting the faith of a majority of religions Americans. In a 2007 survey from the Pew Forum on Religion and Public Life, 78.4 percent of respondents said they were Christian, but only 26 percent identified themselves as belonging to an evangelical church.

Almost 24 percent of the survey's Christian respondents were self-identified Catholics, seemingly the only other Christian denomination Santorum doesn't believe has yet fallen under Satan's sway.

Santorum, along with other conservative Republicans, has declared that Obama is waging a war on religion based on the president's support of a policy of mandatory birth control coverage. However, literally declaring that Satan has taken hold of mainline Protestantism seems more akin to an attack on individuals' religious values than asking employers to cover contraception costs for their workers.