The election of a historically large Republican majority coincided with the lowest turnout in a midterm election since 1942. But the 2014 race for the House played out in two very different sets of states. In the 24 states hosting high-profile, competitive Senate or gubernatorial races, raw votes cast in House races were down an average of 30.5 percent from 2012. But in the 26 states that weren’t, raw votes were down a much more severe 43.9 percent.
The 2014 elections probably won't have any effect on the 2016 presidential contest, but they will have an effect on that year's congressional races. The Republicans will have more incumbents in the House, making their majority highly likely to survive even a good Democratic year. And in the Senate, while the map will strongly favor Democrats, Republicans will have some capacity for absorbing losses.
Thom Tillis won the most expensive U.S. Senate race in history; the campaigns and outside groups spent more than $100 million on the contest. More than 100,000 political ads ran in North Carolina this election cycle, the most of any Senate race. And the state is relatively evenly split among Democrats, Republicans and independent voters.