Amy Sullivan nailed all this writing for The Washington Monthly way back in 2005:

His obstacle is the evangelical base—a voting bloc that now makes up 30 percent of the Republican electorate and that wields particular influence in primary states like South Carolina and Virginia. Just as it is hard to overestimate the importance of evangelicalism in the modern Republican Party, it is nearly impossible to overemphasize the problem evangelicals have with Mormonism. Evangelicals don’t have the same vague anti-LDS prejudice that some Americans do. For them it’s a doctrinal thing, based on very specific theological disputes that can’t be overcome by personality or charm or even shared positions on social issues. Romney’s journalistic boosters either don’t understand these doctrinal issues or try to sidestep them. But ignoring them won’t make them go away. To evangelicals, Mormonism isn’t just another religion. It’s a cult.

Which is why Reynolds’s closing sentiment, much as I agree with it, is just preaching to the right-thinking NYT-readership choir who thinks all this true-believer stuff is silly:

Amid the passions of this election season, it’s time to revive the tolerant spirit of the founding fathers. Religious competition of any kind, they believed, can breed bigotry, repression and hatred. The founders made an earnest effort to keep religion out of politics. Let’s do the same as we carry out the important work of choosing our next president.

The reason Romney hasn’t done much worse with their votes is that Mormons and evangelicals share nearly identical political views and because there hasn’t been a standout social conservative candidate this year.

There are varying degrees of fundamentalism, and polls have shown that most evangelicals would vote for a Mormon in the primary. But they’ve also shown that there’s a significant group that won’t.

There are limitations, of course. If Romney wins the nomination, they’ll fall in line (most of them, I should say).

For evangelicals, just about anything’s better than a pro-choice, pro-gay-rights Democrat, even if it’s a formerly pro-choice, formerly pro-gay-rights Mormon Republican.

* fixed spelling

Ryan Chittum is a former Wall Street Journal reporter, and deputy editor of The Audit, CJR's business section. If you see notable business journalism, give him a heads-up at rc2538@columbia.edu.