Also, can representative government and the idea that all people are created equal be considered Christian ideas? Well, democracy and republicanism existed before Jesus, and the whole deal with the Abrahamic religions isn't very democratic. God isn't in charge because He has the support of the people , but because He created the Universe, which gives Him the right to boss everyone else around. That's pretty much the ultimate absolute monarchy, right there. It could certainly be argued that Christianity is more democratic than the Judaism that preceded it, what with the idea of everyone being equal in Christ. That probably only applied to Jews who followed Jesus, but it's still a step in the right direction, I suppose. On the other hand, though, Jesus and his early followers didn't seem to have a problem with slavery. And despite women being significant in the early development of the religion, a bit of the traditional Jewish thinking about women did continue into Christianity.
A constantly recurring theme in the Bible that I've addressed before but bears repeating is the constant portrayal of women as temptresses. Starting with Eve and continuing with Solomon's wives, Jezebel, and even the metaphorical loose woman of Proverbs, women are always tempting men to disobey God, and the men apparently don't have much choice in the matter. I mean, if some heathen woman says she'll show you her boobs if you worship Baal with her, what man could resist that? The whole reason men aren't supposed to marry foreign women, as indicated in the Bible, is that they might tempt the Jews into going a-whoring after other gods. And really, the idea of men not being at all complicit in their dealings with women is still alive and well today. Come on, that other woman didn't steal your boyfriend; he made the choice to leave you. But you still see references to Angelina Jolie stealing Brad Pitt from Jennifer Aniston, because I guess Brad has no free will. This kind of thinking makes BOTH genders look bad, doesn't it?
Finally, there's the whole privacy issue. Even though it's not directly written in the Constitution, the American government has come to regard privacy as a basic human right, which is why you can no longer be prosecuted for having gay sex in the privacy in your own home. Religion, however, is all about telling people what kinds of sex they're allowed to have. And, of course, nothing can be kept private from God, which has both good and bad aspects. That means there can be a universal concept of justice, which is something that pretty much everyone seems to desire, but it also means that God is watching you do the nasty. Which, when you think about it, is rather disturbing, even if you ARE sticking to the methods of sex that He's deemed acceptable.
 Except in a way it IS an issue of popular support, since a religion has to have a significant amount of followers in order to last. Not all of these followers have to convert willingly, however.