What is a witty, smart answer for someone who thinks they are ALWAYS right?

A family member of mine says things like "People who believe in religion are ignorant!" or "Republicans don't deserve to even be a party!" and I never know what to say shut her up. She will take a stance on something in the minority not because she believes in it, but because she likes to argue and she is ALWAYS right (so she says and has convinced other family members). What are some witty things I can say when she spouts off about this crap?