Competitive House Elections

Notwithstanding such high-profile races such as the Murphy-Tedisco special election in upstate New York, close House elections have become a rarity. In The New York Times, Nate Silver and Andrew Gelman observe:

Consider that, in the past decade, there were 2,175 elections to the United States House of Representatives held on Election Days 2000, 2002, 2004, 2006 and 2008. Among these, there were 41 instances — about 1.9 percent — in which the Democratic and Republican candidates each received 49 percent to 51 percent of the vote (our calculations exclude votes cast for minor parties). In the 1990s, by contrast, there were 65 such close elections. And their number increases the further one goes back in time: 88 examples in the 1950s, 108 in the 1930s, 129 in the 1910s.

They go on to speculate about the reasons for this trend: an increasing incumbency advantage, "sorting out" among voters, and polarization among national politicians. Their analysis should come as no surprise to political scientists, but it is a nice concise summary nonetheless.