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Herman Cain sought to clarify his position on abortion Thursday after one rival seized on comments he made saying that while he opposes abortion, the government shouldn’t decide whether women can terminate their pregnancies.

In an interview Wednesday with CNN, Cain said he believes life begins at conception. "And abortion under no circumstances," he added. But Cain also said "it's not the government's role or anybody else's role to make that decision," according to a CNN transcript.

Asked whether his personal views would become a "directive to the nation," should he become president, Cain said they wouldn't.

"I can have an opinion on an issue without it being a directive on the nation," he said. "The government shouldn't be trying to tell people everything to do, especially when it comes to social decisions that they need to make."

Republican presidential hopeful Rick Santorum pounced on Cain Thursday, saying it mirrors the views of abortion-rights supporters and shows that Cain is not a true conservative.

Cain’s campaign issued a statement later Thursday saying Cain’s answer was focused on whether he as president would “order” people not to seek an abortion.

“The president has not constitutional authority to order any such action by anyone,” he said. “That was the point I was trying to convey.”

“As to my political policy view on abortion, I am 100 percent pro-life. End of story,” he said, adding that he will appoint judges who are anti-abortion.

“I will oppose government funding of abortion,” he said. “I will veto any legislation that contains funds for Planned Parenthood. I will do everything that a president can do, consistent with his constitutional role, to advance the culture of life.”

Campaigning in New Hampshire on Thursday, Santorum accused Cain of misleading voters about his conservative credentials.

"It's basically the position that just about every pro-choice politician has in America," Santorum told The Associated Press. "I don't know too many pro-choice politicians who are for abortion, who want more abortions ... but they say the decision is a choice the government shouldn't be involved in."

Santorum added: "That is Herman Cain's position, which does not make him pro-life. That is the quintessential pro-choice position on abortion."

Santorum said Cain's comments are further proof that Cain hasn't been tested as a candidate.

"This is what you get when folks haven't run for office before -- you get someone who says what he is personally, and no one .... asks the question of whether it applies to his public policy," Santorum said. "And obviously it does not."

Santorum, a former U.S. senator from Pennsylvania, has been campaigning aggressively in early voting Iowa, where he gets high marks from conservative activists but registers little support in public polls. Cain, meanwhile, has been rising in the polls, both in New Hampshire and nationally.

Santorum kept up his criticism of Cain later Thursday, when he filed paperwork with the New Hampshire secretary of state's office to get on the ballot for the yet-to-be scheduled presidential primary. Cain did not file in person; he had a staffer sign him up earlier Thursday.

"I'm not selling any books today," Santorum said, referring to a book tour Cain recently launched that fueled speculation that he was more interested in profiting from his growing national profile than winning the election.

Santorum said it's possible "viral candidates and virtual candidates" can win but that he believes retail politics, particularly in the early voting states of Iowa and New Hampshire, still matter.

"Had Herman been up here doing town hall meetings for a few months we'd know a lot more about him than we do now," he said. "You may not agree with the positions I hold, but you know the positions I hold. And they're very clear, and they're very consistent."

The Associated Press contributed to this report.