McCain backers have said McCain chose Sarah Palin because she’s so much like him. Most important, she seems to have taken on the Republican establishment. But in other ways she represents everything he hates. A few weeks ago, former senator Rick Santorum said that when they served in the Senate together McCain “would often rail against Christian conservatives.” When I saw former Majority Leader Tom Delay, a strong religious conservative, he said something similar: “Issues that are important to me are not important to him.”
And of course he famously referred to Pat Robertson and Jerry Falwell as “agents of intolerance.” It’s worth recalling his words from 2000:

“Political intolerance by any political party is neither a Judeo-Christian nor an American value.The political tactics of division and slander are not our values, they are corrupting influences on religion and politics, and those who practice them in the name of religion or in the name of the Republican Party or in the name of America shame our faith, our party and our country. Neither party should be defined by pandering to the outer reaches of American politics and the agents of intolerance, whether they be Louis Farrakhan or Al Sharpton on the left, or Pat Robertson or Jerry Falwell on the right.”
In a way, it misses the point to say John McCain is uncomfortable talking about his faith; what he’s been uncomfortable with was evangelical Christians.

And then McCain went and picked a movement evangelical. Sarah Palin was a far more serious evangelical Christian than George W. Bush; she’s the first major candidate who comes fully from the religious conservative movement.
Perhaps McCain had just become more comfortable with religious conservatives over the years, or made what he viewed as a Faustian bargain in order to win. Perhaps Santorum, who left the Senate in 2006, was out of date. Perhaps he felt that she had the piety without the judgment of Falwell and Robertson.

Or perhaps he just didn’t know much about this aspect of her. I have no doubt that political advisors told him how popular she’d be with the pro-life community and that he loved the political implications of that. But did he knew that she justified a natural gas pipeline as part of God’s will? Or that she supports the teaching of creationism? Or that she supported a Christian Heritage Week? I’m not saying these views disqualify Palin; I’m saying that until recently they would have led McCain to disqualify Palin.
Of course, even if he’s just learning about these things now, he’s not likely to be too bothered, since it’s clearly part of her appeal. Of all the strange turns of events in the campaign, the idea that McCain would become a hero of the Religious Right is one of the weirdest.