Jacob Hornberger vs. Peter Brimelow on immigration (starts about 20 minutes in)
Hornberger is a fantastic public speaker and easily wins this one.
I've always thought the argument that "they come here to get welfare!" is absurd. Don't they have even bigger welfare states in their own countries? And if being a welfare bum is your goal, why bother with the US when you can go to Canada or anywhere in Europe?