Wow, for a minute there you had me worried I'd been had yet again by another politician. But actually everything you cite says that he wants to leave it up to the states (including the Defense of Marriage Act, which simply gave states the right to not recognize gay marriage). He legitimately supports states rights to do whatever they want, which is also why he voted against the civil rights act. No, I don't think that it's just his way of trying to push immoral things past people, more that he believes people should be able to make good or stupid decisions for themselves (and as a state). Sure, that might mean Mississippi would pass some shitty laws, but it also means the rest of the country wouldn't have to live under those same shitty laws. As we have it now the entire country is fighting tooth and nail for the right to tell everyone else what to do. There's always some bad that comes with the good, but if the federal government would get out of the fucking way it at least wouldn't keep the more intelligent states from enacting sane laws.
Face it, on this issue it isn't about using state's rights to oppress people (he did VOTE AGAINST DON'T ASK, DON'T TELL after all - do you think that was an accident?). Either you think everyone in the country should fight for what the federal government gets to force on everyone else, or else you'd rather just leave it to smaller groups to make good and bad decisions for themselves. Personally I'd choose the later, as I think eventually states would come around and allow things like gay marriage and abortion. Otherwise you're basically just supporting the government's right to tyranny, under the idea that "they will know what's best."