(Gerald Herbert/AP Photo)

CENTENNIAL, Colo. - Employing some of his most conservative rhetoric to date, Mitt Romney referred to morning after pills as "abortive pills" during a speech at a rally in Colorado where he told the crowd about the importance of electing a president who will protect the "right to worship God."

"I'm just distressed as I watch our president try and infringe upon our rights, the First Amendment of the Constitution provides the right to worship in the way of our own choice," Romney said to nearly 3,000 people gathered in the gymnasium of Arapahoe High School, in Arapahoe County, an area known as a so-called "swing county" that Obama won in 2008.

"This same administration said that the churches and the institutions they run, such as schools and let's say adoption agencies, hospitals, that they have to provide for their employees free of charge, contraceptives, morning after pills, in other words abortive pills, and the like at no cost," Romney said. "Think what that does to people in faiths that do not share those views. This is a violation of conscience.

"We must have a president who is willing to protect America's first right, our right to worship God according to the dictates of our own conscience," he said.

Romney was referring to the plan by the Obama administration to require any church-affiliated employers to include coverage for birth control that was pushed forward in January and is set to go into effect in August. The issue was brought up again when leaders in Catholic churches across America read letters from the church's leadership on Sunday, Jan. 29, condemning the administration's policy.

Until now, Romney has not spoken about the mandate at any of his campaign events, but he did in an op-ed he wrote in the Washington Times in which he condemned the policy.

"And on day one I will eliminate the Obama administration rule that compels religious institutions to violate the tenets of their own faith," he wrote. "Such rules don't belong in the America that I believe in."

While a Romney aide said the former Massachusetts governor was simply addressing the issues of the day during the rally, the candidate's overtly conservative language seemed to suggest a continuing desire to appeal to the conservative base of voters, a contingent he played well with in Nevada's caucuses last weekend. Romney's remarks also come after a day in which his campaign sought to challenge former Pennsylvania Sen. Rick Santorum's status as a conservative in press conference calls and opposition research e-mails.

Romney also renewed his attacks on the administration's attempt to determine who qualifies as a "minister," a reference to the controversial case involving Michigan schoolteacher Cheryl Perich that resulted in the Supreme Court applying the "ministerial exception," a ruling the administration had opposed. Romney first critiqued the administration's opposition to the Perich case at a meeting of evangelical voters at a Faith and Freedom Coalition event in Myrtle Beach, S.C., in January.

Perich was fired by a school run by the Hosanna-Tabor Evangelical Lutheran Church. Perich, who suffered from narcolepsy, was told she would be fired if she did not submit to an agreement that would give her some money for her health care in return for her resignation.

Perich, however, turned to the federal Equal Employment Opportunity Commission, which filed suit on her behalf, arguing that her firing was in violation of the Americans With Disabilities Act. But when the case went to the Supreme Court, the justices ruled unanimously against Perich, Chief Justice John Roberts writing in the court's opinion that the First Amendment bars "the government from interfering with the decision of a religious group to fire one of its ministers." The Supreme Court ruled that, "the church must be free to choose those who will guide it on its way."

"Did you understand that this administration argued before the Supreme Court that a church should not be able to determine who their ministers are but that government should decide who qualifies," Romney said of the Perich case, as members of the audience booed audibly.

"And by the way, you know that some of the members of the court are pretty liberal. You know what they decided? They decided 9-0 President Obama was wrong," Romney said.