Sure, most everyone is talking politics and Wall Street, but the news also makes it a great time for comedy, and there’s plenty of new stand-up and sketch comedy on TV this weekend, with the debut tonight at midnight of Down and Dirty with Jim Norton on HBO, Louis C.K.’s brilliantly brutal new hourlong special, Chewed Up, at 11 p.m. Saturday on Showtime, a special all-politics edition of MADtv on FOX, and the fourth consecutive new episode of Saturday Night Live on NBC. You can count on me to break down the best and worst moments of it all right here.