Things have gotten so bad, we are told, that the Thanksgiving table is now a battlefield. Advice columnists, psychologists, therapists, podcasters and philosophers counsel us how to avoid or defuse arguments about politics. But sparring at (or about) Thanksgiving isn't new. It is, in fact, a very old tradition -- no less American than pumpkin pie. Debates were on the menu even before Congress formally declared the federal holiday in 1941.