Joined: July 2005
Krauthammer has written on this and similar subjects before. There are definitely people out there who are conservatives on fiscal, military, or foreign policy issues but will have absolutely no truck with the religious right.
I'm politically liberal/progressive myself (I land far into the "left-libertarian" corner of the spectrum at Political Compass). I was raised a liberal Catholic, and sporadically attend a Unitarian Universalist church, arguably the most theologically liberal church denomination one will find in the U.S. But, I've certainly met Republican-voting UUs. They tend to be a minority, but in some larger UU fellowships, political conservatives are a large enough minority to have their own support groups.
I've also met a few vociferously atheist conservatives, who generally come from the libertarian corner of the right. And, religious issues aside, conservatives tend to be strongly pro-business, and crappy science education is hardly conducive to a first-class workforce. Conversely, there's also a segment of the left that promulgates anti-science views (though usually for secular reasons), a group that was well and duly skewered by Alan Sokal in Social Text a few years back. Sokal, incidentally, is himself a self-described leftist.
And, large segments of both the liberal and the conservative American populations take the Constitution quite seriously, and will express public opposition to attempts to privilege religious doctrines in U.S. public school systems.