David Brady says:

The Democrats at this point, all the Democrats like Obama. Republicans don’t like Obama; next to George W. Bush he’s the greatest divider since we’ve been doing public opinion. That is, subtract the percent of his party that like him, minus the percent of the other party that doesn’t like him—so if it’s 90%-10%, there’s an 80-point gap. The third and fourth highest gaps are Obama, so Obama is a divider.

Far be it from me to criticize David Brady, a political scientist who knows much more about American politics than I ever will, but . . . I think it’s a bit silly to call Obama (or Bush, for that matter) a “divider.” The whole point was that partisans have been divided for awhile and there has been a gradual increase. Saying people are divided is one thing, saying Bush and Obama did it is another.

Brady continues:

I believe that there has been an increase in partisanship. So, for the first time, with President Bush we began to see statistically significant differences. When you asked Democrats what they thought of the economy under Bush, it was horrible; when you asked Republicans, it was not so bad; so that the partisan preferences actually drove the perception of the economy. And that’s the first time that had happened in all of our polling data. So, that’s new.

Huh? In our book we cite data from 1988 (by way of Larry Bartels); see the quoted passage here. I can well believe that partisan divisions are getting worse but they’re not new. It must depend on how you measure it, if Brady is claiming there were no such differences before 2000.

In fairness to Brady, this was a live interview, not a written article, and it’s natural to get things a bit garbled in speech. If you were to transcribe everything I said in conversation, you could catch a lot of mistakes from me too.

Thus, the point of this post is not to criticize Brady but rather to clarify some of the issues that he raised.

[Cross-posted at The Monkey Cage]

Andrew Gelman

Andrew Gelman is a professor of statistics and political science and director of the Applied Statistics Center at Columbia University.