>>> to presidential politics now and the continued rise of the culture wars on the campaign trail. tonight the obama campaign is lashing out at rick santorum over comments about the president that santorum says were misinterpreted. nbc's ron mott has the details on the trail for us tonight in ohio.
>> it's about some phony ideal, some phony theology.
>> reporter: after saying the president's energy philosophy was based on a phony theology saturday --
>> i wasn't suggesting the president is not a christian.
>> reporter: rick santorum had a real challenge, separating religion from theology, no less on a sunday.
>> senator, what in the world were you talking about, sir?
>> i was talking about the radical environmentalists.
>> your use of the word "theology" do you wonder that might lead some people to suggest that you were questioning the president's faith?
>> well, no, because i've repeatedly said i don't question the president's faith. i've repeatedly said that i believe the president is christian. he says he's a christian. but i am talking about his world view .
>> reporter: each of the republican candidates has voiced disapproval of the president's stance on energy and the environment. only santorum who serves in the polls after winning an election trifecta has linked him to theology.
>> a different theology.
>> reporter: the former pennsylvania senator not only explained his use of that word this morning, he also answered to critics questioning his theory that prenatal care leads to more abortions.
>> the bottom line is that a lot of prenatal tests are done to identify deformities in utero and the customary procedure is to encourage abortions.
>> reporter: meantime, mitt romney remained out of the spotlight sunday in utah, where he took part in tenth anniversary celebrations this weekend for the '02 winter olympics . back on the campaign trail --
>> thank you very much.
>> reporter: ron paul played to large crowds in missouri saturday before heading to north dakota today, while newt gingrich focused on his home state of georgia , citing the importance of home field advantage .
>> if any of the three of us loses our home state, if santorum loses pennsylvania, romney loses michigan or i lose georgia, you have, i think, i very, very badly weakened candidacy for any one of the three of us.
>> reporter: this could be a crucial week in the campaign. there is a debate scheduled for wednesday in arizona. it's the only debate between now and super tuesday, lester.
>> all right, ron, thank you.