The survey also contained a few basic questions on politics. I made an index of political views from questions on approval of President Bush, party identification, and description of political views as liberal or conservative. Controlling for age, gender, education, income, and race (black vs. all others), people who have read more of these authors were more liberal/Democratic. It was the second strongest predictor, exceeded only by race.
I also did a regression with a separate variable for each author, which produced a significant improvement in fit. The biggest effects (positive numbers mean a liberal/Democratic direction and negative mean a conservative/Republican direction):
That's six more or less contemporary authors plus Flaubert. At first glance, it seems odd to have Flaubert in a group with Stephen King and Danielle Steel, but I think they have something in common--compared to most of the other authors on the list, they're less likely to be required reading in high school or introductory college English classes, so people have to make a more active choice to read them. The relationship to political views doesn't correspond to the political views of the authors--for example, Bellow was pretty conservative by that time while Michener was an active Democrat.
I wasn't surprised to find some relationship between reading and political views, but I was surprised at how strong it was. Among people who hadn't read Flaubert only 8% were liberal Democrats who disapproved of Bush; among people who had, 34% were.