There are good reasons to separate state from church but politicians running for office in the United States often forget them. Barack Obama, scorched by his association with the Rev Jeremiah Wright, found out weeks ago. Today, however, it is John McCain doing some urgent pastoral penance.

Mr McCain, the Republican nominee, has had to untie himself from two preachers whose backing he once actively sought. He fell into temptation believing that by accepting their endorsements he would win the affection of Christian conservatives sceptical about his candidacy. But he did not properly anticipate the cost of accepting them. If you have seen the video clips of Mr Wright blurting biblical condemnations of America, you might be startled by the rantings now surfacing from the dubious duo of McCain Christian backers, the Revs John Hagee and Rod Parsley.

Late on Thursday, Mr McCain was forced to issue successive statements renouncing the endorsements of both men. Thus, he finds himself with a pastor problem just like Mr Obama. But unlike the Democrat Senator from Illinois, he at least was not a member of either man's church nor does he have children baptised by either of them. To that extent, at least, the damage may be less significant.

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But embarrassed he certainly is. It was only in February, during a campaign visit to Cincinnati, for example, that the senator appeared on stage with Mr Parsley, of the World Harvest Church of Columbus in Ohio, calling him "one of the truly great leaders in America, a moral compass, a spiritual guide".

And his courtship of Mr Hagee is also well documented. Addressing his Christians United for Israel Church last year, he thanked the pastor for his "spiritual guidance to politicians like me", saying that "it's hard to do the Lord's work in the city of Satan". That would be Washington DC, of course.

His strategy bore fruit and the two men endorsed him, giving his campaign hope that conservative Christians might at last be rallying to his cause. What a pity, then, that in this digital age, there was no suppressing the wackier notes each of them have struck from their respective pulpits.

Worrisome utterances by Mr Hagee have been circulating for months, notably his suggestion that the Catholic Church was the whore of the world. Last week, more of his views began to surface and any notion of keeping Mr Hagee on the McCain roster of supporters became quite impossible. It was all about how Hitler and the Holocaust were all part of God's plan to dispatch the Jews back to Israel.

In a sermon from nearly 10 years ago, Mr Hagee said the Holocaust had been foretold in the Bible. "How is God going to bring them back to the land? The answer is fishers and hunters," he said in reference to the creation of modern Israel. "A hunter is someone who comes with a gun and forces you. Hitler was a hunter."

An uncomfortable McCain was asked about it during a campaign appearance in California.

"I just think the statement is crazy and unacceptable," he responded. "I would reject the endorsement of the expression of those kinds of views." In a statement later, he claimed he had known about Mr Hagee's views before accepting his endorsement. "Obviously, I find these remarks deeply offensive and indefensible," he said.

And before you could say "Amen" another statement was landing on the desks of reporters, similarly rejecting the endorsement of Mr Parsley. Suddenly, he was no longer a "truly great leader" but rather an electoral liability. The snippets broadcast on ABC television earlier in the day saw him terming Islam the "anti-Christ" and Mohamed "the mouthpiece of a conspiracy of spiritual evil".

At least now the perils of seeking endorsements from the cloth should be clear to the candidates of both parties. "This is a perfect example of when politicians and religious leaders try to use each other and end up getting hurt," said Rev Welton Gaddy, president of the Interfaith Alliance.