A very enjoyable account of their conversation from The Rumpus:

Spiegelman has drawn Santa pissing in the snow next to a “Remember the Homeless” sign, Bill Clinton getting a blowjob in front of a firing squad. In regard to a published New Yorker cover depicting a Hassid kissing an African-American woman, Spiegelman says a girl wrote him a letter saying how nice it was for him to have drawn Abraham Lincoln kissing a slave.