My girlfriend is a liberal and I don't feel like inviting her down south to visit my family.
What if this just creates more conversation I have with your family?
Possible, but I think they will be uncomfortable around her.
At the end of the day it's your girlfriend, someone that potentially might spend the rest of her life with you. That's said who cares about your family. You should support you partner and who knows maybe your family will like her anyways regardless of the difference in political stance.
I'm not sure. I think it's best if I don't bring her to family gatherings
I feel you should think on this, if you keep your girlfriend away from your family she'll never get to know them. If you want a serious relationship, having family involved is an important part.