Okay, I try to look at it from this angle. Take it how you will.

I'll use this scenario as an example:
If a man was standing atop the empire state building, about to jump down to his death, would you try to talk him out of it, or do what you can to save him, even if he did not want your help?

Most people would step in and try to save this man's life, even if he was not thankful for it later. Why? Because it is the right thing to do.

I can't speak for all Christians, but by making gay marriage illegal, they believe they are doing this exact same thing. Their interpretation of the bible causes them to believe that homosexuality is a sin, and people who live in sin go to hell by their view. They actually believe that they are saving lives. It may be a few, but according to them, if they save even just one single life, it's worth it.

Yes, some of those people picketing around the white house are bluntly prejudice. They don't give a crap about God or the bible. But for the majority of Christians, whether you believe it or not, they are actually trying to do the right thing in their mind, whether you think it's right or not.

So before you call them bigots, or discriminatory, think about it. I'm not saying that they're right for doing the things they do, but it is certainly not because they hate gay people.