What are some good arguments against "if you don't like it, leave!" and...

The more tyrannical the government, the less this is an option. Your opponent might say something like, “OK, well, this is America and you’re free to leave any time, so what are you still bitching about?” but that’s not the point. The point is that “If you don’t like it, go somewhere else” can’t actually be any kind of guarantee of freedom for the reason given above. If our country really is going to hell in a hand-basket and descending in to tyranny, we won’t be able to leave unless we had a crystal ball and could foresee the future. It’s a bit overplayed but absolute relevant… just point to the rise of the Nazis. At first, they seemed like a marginal party. When they took over, they really weren’t saying anything that controversial at the time and the anti-semitic rhetoric fell on Germans’ ears of the day no harder than the anti-immigrant rhetoric of the US regime falls on American ears.

We - and pre-WWII Germans - can hardly be blamed for not owning functional crystal balls!

See this thread.

Clayton -