August 18, 2016


How A Trump Debacle Could Affect The House And State Legislatures (Seth Masket, 8/17/16, 538)

In a 1986 paper, political scientist James Campbell sought to measure the coattail effect and found that each additional percentage point that the presidential candidate won was commensurate with a three seat gain in the House. It's possible that this effect has waned somewhat in recent years with the rise in polarization and the number of safe seats. (The scatterplot above suggests the relationship is more like two seats for each percent of the vote today.) There are fewer massive seat shifts in the House during presidential elections than there used to be, but there are also fewer presidential blowouts.

So what might this year look like? Republicans, with 247 of the House's 435 seats and 4,125 of the states' 7,383 legislators, are certainly exposed.1 Trump's polling numbers aren't great, but there are so many factors that make him an unusual candidate, from his rejection of many core conservative principles to his lack of support from several prominent Republicans. We've really not seen a candidacy quite like his at the presidential level.

But we have seen it at the state level. Colorado provides us with a couple of useful recent examples. One is the state's 2010 gubernatorial race, in which Dan Maes, widely seen as an unqualified and irresponsible candidate for governor, nonetheless won the Republican nomination. Instead of trying to coach him or prop him up, most party leaders quickly abandoned him and championed former Rep. Tom Tancredo, the nominee of the American Constitution Party, as the "real" Republican in the race. They also diverted campaign resources into state legislative races. The result: Republicans badly lost the gubernatorial race despite a strong national Republican tide. But the GOP actually picked up a net of one state Senate seat and five state House seats, seizing narrow control of the lower chamber.

In 2004, Colorado Democrats targeted key state legislative races and channeled millions of dollars their way. Despite President George W. Bush's winning the state by nearly 5 percentage points, Democrats managed to seize seven state House seats and one state Senate seat, taking control of both chambers for the first time in four decades. The top of the ticket doesn't have to dictate what happens below.

As we're seeing in several races this year, it's tricky for Republican candidates to simultaneously run with their party while running against their national ticket. But it's not impossible.

Posted by at August 18, 2016 3:36 PM