The take-home message of Mitt Romney's recent speech on religion and politics was pretty clear: I may be a Mormon, but at least I'm not an atheist.

Romney sought to strengthen his advantage as a presidential candidate known for being religious while assuaging the concerns of Americans who are reluctant to vote for a Mormon. He did so by reinforcing the public's longstanding prejudice against unbelievers, arguing that religion -- any religion -- is preferable to no religion at all.

According to an August survey by the Pew Center on Religion and Public Life, nearly half of those who express an opinion describe Romney as "very religious," and "most Americans continue to say that it is important for a president to have strong religious beliefs." At the same time, one in four Americans say a candidate's Mormonism would make them less likely to vote for him, and this aversion is especially strong among voters for whom a candidate's religiosity matters most: More than a third of white Republican evangelicals, who play an important role in choosing their party's nominee, are leery of Mormon candidates.

But the same survey that highlighted this problem also suggested a solution. "Being a Mormon is viewed as far less of a liability for a presidential candidate than not believing in God or being a Muslim," the Pew Center noted.

Bashing Muslims would fly in the face of the distinction President Bush always has drawn between violent jihadists and their moderate co-religionists. In his speech, Romney took the same tack, condemning "radical Islamists" while admiring ordinary Muslims' "commitment to frequent prayer" (along with Catholics' "profound ceremony," Pentecostals' "tenderness of spirit," Lutherans' "confident independence" and Jews' "ancient traditions").

Romney made no such distinctions in his treatment of atheists, who get even worse poll ratings than Muslims. While "45 percent express reluctance about voting for a Muslim," the Pew Center reports, "61 percent say they would be less likely to support a candidate who does not believe in God."

In a December 6-9 Gallup poll, nearly half of the respondents endorsed an even stronger anti-atheist statement, saying they would refuse to vote for "a generally well-qualified person" of their own party "who happened to be an atheist." The corresponding number for a Mormon candidate was 17 percent, about the same as before Romney's speech.

Romney tried to build on this advantage, wrapping together all religions, except for "the religion of secularism," in a warm, fuzzy package. "Any believer in religious freedom, any person who has knelt in prayer to the Almighty, has a friend and ally in me," he said. "We do not insist on a single strain of religion; rather, we welcome our nation's symphony of faith."

Americans who have never "knelt in prayer" clearly should not bother auditioning for the "symphony of faith." Romney conspicuously failed to address the question of whether they also are excluded from his circle of friends and allies.

Romney's justification for treating all religions as presumptively good, no matter how wildly contradictory their teachings, is that they all share a "common creed of moral convictions." He enumerated three: "the equality of human kind, the obligation to serve one another and a steadfast commitment to liberty." Yeah, there's no way an atheist could believe in those things.

To back up his claim that "freedom requires religion just as religion requires freedom," Romney cited John Adams' comment that "our Constitution was made only for a moral and religious people." Adams, a Unitarian who rejected orthodox Christian beliefs (including the divinity of Christ, which Romney was at pains to affirm), valued religion in general because he believed it restrained "human passions" such as "avarice, ambition, revenge or gallantry."

Like other founders who leaned toward deism or agnosticism, Adams thought religion was important not because it was true but because it helped keep the common people in line. Romney's promiscuous ecumenism suggests he holds a similar view.