I go to an American university. I'm getting a master's degree in Social Work, so it's basically a forgone conclusion that the professors are liberals. The rare occasions that I find ones that aren't, are pretty memorable.
When I was in undergrad, I was a history major and it was pretty much 50/50. I liked those odds better personally because I'm a Christian conservative. All but one of my professors in undergrad were happy to let anyone believe whatever they wished; graduate school is far less tolerant and I find myself just keeping my mouth shut most of the time.
I don't really worry about my kids going to a university filled with liberals and atheists. By age eighteen, I would hope that I would have given my kids enough exposure to the church and the Holy Spirit that they would be able to hold onto who they are while under fire.
As young children, I would be less crazy about it. Fortunately, where I live, elementary school teachers in general seem to be a pretty Christian sort of people. While some of them have ideas I disagree with, they tend to stay away from controversial subjects around the kids.
I guess it would depend on the school curriculum. I don't think atheists and liberals have cooties, I'm fine with my kids learning the three r's from them. But I would never send my kids to a private school for atheists or anything.