I am an atheist, but think I would rather live in a country governed by christian values than one not.
There's no such thing as "Christian values." People live by cultural values and then cherry-pick the parts of their religion that fit and highlight those. The Bible is so packed with conflicting ideas that every Christian has to choose which ones to take literally and which ones to ignore.
Take the Bible, filter it through the right obfuscated mish-mash of theological ramblings, and presto, you've got a religious justification to take credit for your culture's values --
no matter what they are. Currently they've swept most of the stoning and smiting under the rug, but they've moved the couple of sentences about homosexuality front and center! The beautiful irony is that Ted Haggard was a part of that campaign to build the hatred he's now facing.
We could just as easily pull values from the Bible which make Saudi Arabia look like a nation of rowdy liberals. "Chistian values" could mean having your slaves throw stones at people who kiss before they're married.
We are not a nation of Christian values. We are a nation of American values. Christianity tries to take all the credit, but that's bullshit. Thank goodness we have enough real Americans to oppose the Christian extremists who are trying to use the undeserved good reputation of Christian values to push a radical anti-science agenda. In fact, if any values can be called distinctly Christian, they're the ones involving hatred of gays or Jews, or any other stupid values which appear in religion but not among clear-thinking people. But even those can't really be called "Christian values" because they're shared with Islam and various other, less successful cults.
By the way, I don't give a rat's ass about what the founding fathers said about Church and State. (Although the greatest of them were not very religious at all.) Church is f'ing stupid, and it shouldn't influence government policy whether people knew that in the 1770s or not. The separation of Church and State has been framed as a constitutional issue because that's the best way to deal with it in the courts. But the real justification for promoting it is that faith is crazy and very harmful.
By the way, tolerance is overrated, or at least in the typical sense of misusing the word to mean "respect." I tolerate religion in that I don't go out and impede people from practicing it. But I refuse to
respect it, and a lot of people have confused disrespect with intolerance.