You can listen to it here. And you should.
Maron (measured, direct, and fair—I love him) questions Gallagher about his history, the mechanics of comedy, and finally—as the interview builds toward Gallagher's abrupt exit—some of his more controversial material. Gallagher rants about sub-atomic particles (electrons are giving us cancer) and Teenage Mutant Ninja Turtles (apparently they screwed him out of some money—for pizza, probably) for the first ten minutes or so, and then it gets to the political stuff.
You should definitely listen to it if you're interested in this at all. It's a really dramatic, sad interview.
Gallagher has eight main defenses—which you can learn about after the jump.