Alternatively you could treat her like a human being instead of a political enemy.
I think she sacrificed that personal privilege when she decided that I'm not entitled to being treated like a human being myself based on something I can't control.
You didn't actually say what she's done beyond obnoxious Facebook posts. What exactly has she done to you? If its really, really bad, then by all means don't invite her... but then again, that would have little to do with her obnoxious Facebook posts.
If it wasn't that bad, then just suck it up and put up with her. Most people have to put up with some boorish relative around the holidays (mine's a NWO conspiracy theorist
). Love your enemies, turn the other cheek etc. Just be the better person. Besides confrontations are almost never as satisfying as they are in your head.