How not to win an argument:
Practical lessons learned from shabbos in Flatbush

1. Insinuating that someone's opinions are not their own ("Your girlfriend convinced you of this, didn't she?") or that someone will grow out of their opinions ("Let's have this conversation again when you're 50"), is very insulting. Even if it might be correct, it's not gonna successfully convince the people you're insulting of anything. Treat me like an adult and maybe I'll treat you likewise.
   
2. If you want to make negative comments against a group and have me believe you, call them by a nice name. If the guy making observations about black politicians during kiddush had said "black politicians" instead of "shvartze politicians", I would have been much more believing that he had correctly interpreted his experiences with those politicians.