RealClearPolitics Cross Tabs Blog

« Cheney May Not Attend GOP Convention | Cross Tabs Blog Home Page | Please Explain the Constitution to Gloria Steinem »

Myth of the Democratic Landslide

By Brendan Nyhan

John Sides reiterates an important point: the perception that Barack Obama "should" be winning by a huge margin (echoed today by David Brooks) is not supported by empirical evidence. The leading statistical models of presidential election outcomes forecast a narrow Obama win.

The consequences of this are actually more serious than most people realize. In the seminal work on mandates, Jim Stimson, David Peterson and two other political scientists argue that "mandates" are a collective interpretation of election results that carries an informational signal to nervous incumbents worried about re-election. As a result, members of Congress briefly shift their voting behavior in the direction of the perceived mandate (the three times in which this happened, Stimson et al argue, are 1964, 1980, and 1994). With expectations about Obama so high, there's almost no way that anything short of an LBJ-esque landslide will be perceived as a "mandate," which will make it harder for him to enact his legislative agenda.

Brendan blogs regularly at