There's nothing new, of course, about the Christianization of the GOP. Seven years ago, when debating Al Gore, then-candidate George W. Bush was asked to identify his favorite philosopher and answered "Jesus." This year, however, the Christianization of the party reached new heights with Mitt Romney's declaration that he believed in Jesus as his savior, in an effort to stanch the flow of "values voters" to Mike Huckabee.

My concern isn't the rift that has opened between Republican political practice and the vision of the nation's Founders, who made very clear in the Constitution that there would be no religious test for officeholders in their enlightened new republic. Rather, it's the gap between the teachings of the Gospels and the preachings of the Gospel's Own Party that has widened past the point of absurdity, even as the ostensible Christianization of the party proceeds apace.

The policies of the president, for instance, can be defended in greater or (more frequently) lesser degree within a framework of worldly standards. But if Bush can conform his advocacy of preemptive war with Jesus's Sermon on the Mount admonition to turn the other cheek, he's a more creative theologian than we have given him credit for. Likewise his support of torture, which he highlighted again this month when he threatened to veto House-passed legislation that would explicitly ban waterboarding.

It's not just Bush whose catechism is a merry mix of torture and piety. Virtually the entire Republican House delegation opposed the ban on waterboarding. Among the Republican presidential candidates, only Huckabee and the not-very-religious John McCain have come out against torture, while only libertarian Ron Paul has questioned the doctrine of preemptive war.

But it's on their policies concerning immigrants where Republicans -- candidates and voters alike -- really run afoul of biblical writ. Not on immigration as such but on the treatment of immigrants who are already here. Consider: Christmas, after all, celebrates not just Jesus's birth but his family's flight from Herod's wrath into Egypt, a journey obviously undertaken without benefit of legal documentation. The Bible isn't big on immigrant documentation. "Thou shalt neither vex a stranger nor oppress him," Exodus says the Lord told Moses on Mount Sinai, "for ye were strangers in the land of Egypt."

Yet the distinctive cry coming from the Republican base this year isn't simply to control the flow of immigrants across our borders but to punish the undocumented immigrants already here, children and parents alike.

So Romney attacks Huckabee for holding immigrant children blameless when their parents brought them here without papers, and Huckabee defends himself by parading the endorsement of the Minuteman Project's Jim Gilchrist, whose group harasses day laborers far from the border. The demand for a more regulated immigration policy comes from virtually all points on our political spectrum, but the push to persecute the immigrants already among us comes distinctly, though by no means entirely, from the same Republican right that protests its Christian faith at every turn.

We've seen this kind of Christianity before in America. It's more tribal than religious, and it surges at those times when our country is growing more diverse and economic opportunity is not abounding. At its height in the 1920s, the Ku Klux Klan was chiefly the political expression of nativist Protestants upset by the growing ranks of Catholics in their midst.

It's difficult today to imagine KKKers thinking of their mission as Christian, but millions of them did.

Today's Republican values voters don't really conflate their rage with their faith. Lou Dobbs is a purely secular figure. But nativist bigotry is strongest in the Old Time Religion precincts of the Republican Party, and woe betide the Republican candidate who doesn't embrace it, as John McCain, to his credit and his political misfortune, can attest.

The most depressing thing about the Republican presidential race is that the party's rank and file require their candidates to grow meaner with each passing week. And now, inconveniently, inconsiderately, comes Christmas, a holiday that couldn't be better calibrated to expose the Republicans' rank, fetid hypocrisy.