Churches and religious organizations from all points of view often endorse one candidate or party over another. My earlier post on Catholics and Dems versus Reps makes illustrates this point within a particular tradition.
But what does this say about the variegated philosophies of what separation between church and state actually means? Are they completely separate spheres, one caring for the soul and the other for the body, as the Lockean perspective suggests? Or, are things more complicated than that? Indeed, the Lockean perspective applies only if one thinks of religion as a completely private thing, but anyone who studies religion realizes this ultimately derives from a particular perspective of Christian Protestant belief, whereas other Protestants, Catholics, Orthodox, Muslims, Jews, Hindus, Buddhists, Daoists, Taoists, etc., may disagree, saying that their "religion" encompasses an entire way of life, both private and public.
Whether we find evangelical groups supporting McCain (something that is highly ironic, as I have noted so many times--just follow the tags on "McCain" where they match up with "Evangelicals"), or, where I occasionally attend at the Riverside Church, where I have seen both Bill Clinton and Hillary Clinton as guest speakers, although technically after the service was completed in a "town hall meeting" that happened directly after the benediction.
The interrelationships between church and state have been, are, and probably always will be convoluted, complicated, and labyrithine. But whether or not religious groups violate the wall of separation between church and state when the politick in the pulpit, they do violate the tax code! That's right! Under President Johnson, the tax code was revised to state that for a not-for-profit organization to maintain tax-exempt status, the organization, at least, may not support or oppose a political party or politician. But now many evangelical preachers are blatantly disregarding this to a degree unheard of before--they are actually sending the IRS a copy of their sermons that support John McCain and a copy of the tax code with that line crossed out. They are making a clear call for revision.
See full discussion in NYTimes here.