What Taner Edis says. Basically, there the hard-core is pretty small, but in the right situation, they might get the moderate conservatives to go along with their craziness:

Most Muslim populations I know about are similar: only a relatively small population is rigorously observant. The rest typically acknowledge that the observant ones are the better Muslims, like the fact that at least some in the community are holding up the more rigorous ideals, but are generally happy to go through life as sinners. A similar relationship is true for many Jewish populations, where the Orthodox are acknowledged as the more authentic representation of the faith but do not get too many converts from among more worldly Jews. This pattern seems to be stable, and could remain so for American evangelicals.

The political significance of this pattern of religious overachievers and more lukewarm masses of less committed believers is less clear. I think it depends a lot on the context. Every now and then, the lukewarm masses get caught in a moral panic, and look favorably on the more morally pure taking charge. For example, many Muslims support hardline Islamists in an election even if they don’t like the full package—they’re just sick of all the corruption and think a more religious leadership will be less interested in lining their own pockets.

If you look at surveys about people’s opinions on basic civil liberties, it’s frightening how many are lukewarm about about freedom to criticize the government, right to a fair trial, and so on. However, it’s not that they’re out agitating to abolish these freedoms. In the short term, such people look harmless. You wonder what they’d do in a crisis, though.

This is something I wrote about over a year ago. It’s not the hard core that scare me, it’s the passive ones. In my interactions with the local Campus Crusade guys, I meet some real crazies, but you also meet people who are serious enough about religion to have thought about the issues a lot and realize they’re never going to get along with the crazies. But there are plenty of passive believers who can be stirred up based on reflexive assumptions that Christianity is good and atheism is bad, the sort of people Elizabeth Dole is trying to stir up. They could do some damage, given the wrong historical turn of events.