Republican leaders should squelch any talk of Mike Huckabee's running as the vice presidential candidate. The way he used religion as a weapon in the primaries against Mitt Romney will undo him, as more people think about the meaning of such tactics.

In the Iowa caucuses, Huckabee's campaign and supporters stirred up anti-Mormon sentiments. The former Baptist preacher billed himself as the "Christian candidate." Some evangelicals took the opportunity to question LDS beliefs and express doubts that Mormons are truly Christians. In a New York Times interview the former Arkansas governor himself wondered out loud about LDS teachings on Lucifer. He apologized for that, and now he says he didn't mean to slam Romney's faith.

I can't really buy it. Huckabee is too gifted a communicator -- and as a former minister, too knowledgeable about religious issues -- to have been ignorant of the impact of his words and the actions of some of his supporters.

Some might say that anti-Mormon prejudice would have plagued Romney anyway. But when Morris Udall ran for president in 1976, his LDS faith never became an issue. Many Americans may not understand Mormonism, but widespread anxiety about it was dormant and might well have slumbered on through 2008. Huckabee woke it up.

Republicans must realize this tactic reverberates for people of all faiths. As a Roman Catholic, for instance, I'm now very suspicious of Huckabee. Some of his supporters who think Mormons aren't Christian also think we Catholics also are not Christian. Huckabee has protested that he didn't mean to alienate Mormons, and I'm sure he'd say the same about other faiths. But in a political campaign he raised the dangerous specter of religious issues. He's like a man who strikes a match in a fireworks factory, and wonders why that causes a big fuss.

Anti-Catholic prejudice has stalked the campaign trail before. After the Civil War, James G. Blaine stoked anti-Catholic sentiment in a political career that culminated in 1884 with the Republican nomination for president. Al Smith's Catholicism was an issue when he was the Democratic candidate in 1928. John Kennedy confronted prejudice in 1960. Anti-Catholicism has been deeply buried since then, but who knows if it could be revived?

I for one am suspicious of Huckabee, even when he says something I generally approve of. Take his comments recently at Thomas Road Baptist Church, the church of the late Jerry Falwell, in Lynchburg, Va. Huckabee said, at one point, "I hope you know Jesus Christ personally, because the level to which he rules you and governs you, you need less and less of man's law to tell you how to live and that is what our Founding Fathers understood and we must understand."

I agree with him (and the founders) that a strong morality lessens the need for strong government. But "knowing Jesus personally" also raises my hackles. Some evangelicals charge that we Catholics don't know Christ "personally," meaning, again, that we aren't really Christians. To add to the insult, a further implication is that we're mindless sheep following the church hierarchy.

That's why, right now, Huckabee is the political equivalent of nuclear waste. He'd contaminate any Republican ticket.

Don't think it couldn't happen? Go back to Blaine. Running for president, he became associated with a preacher's comment that Democrats were the party of "rum, Romanism and rebellion." Enough Roman Catholics took offense that Blaine lost the election. Huckabee is today's walking, talking equivalent.

This isn't just a Catholic thing or a Mormon thing. Once religion enters politics, it will affect mainline Protestants, Jews, Muslims, atheists and everyone else.

The main beneficiary of a McCain-Huckabee ticket would be Barack Obama. He has made his mantra the surmounting of divisions in America. He will be saying he can end acrimony as the GOP runs a politician who has played to the most bitter and dangerous emotions in public life.

Sen. John McCain could show that he is truly presidential by making it clear he won't pick Huckabee as his running mate. Failure to do so could guarantee that in January 2009 an ultra-liberal would move into the White House.

That would have one religious benefit: On the first Wednesday in November, many of the conservative faithful would be down on their knees, praying harder than they have for a long, long time.