Can I tell our college president about my girlfriends professors behavior?
Is everything okay. Why do you want to tell your college president about your professor?
I'm going to talk with her about my girlfriend, because he insults her a lot
If your girlfriend's professor is being negative towards her, then you should speak up against it. If you don't then he could become worse and worse to her believing that he can get away with it, and it is completely normal to want to stop this from happening to someone that you love.
I hate people who tolerate haters, he has to be stopped.
He does need to be stopped. It is good that you are doing your best to protect your girlfriend.