To generate a forecast for 2014, we assumed three things: that Obama’s approval in June 2014 will be what it was in November 2013 (42 percent), that the economy will grow at the same rate in the first two quarters of 2014 as in the second and third quarters of 2013 (0.7 percent, non-annualized), and that this Roll Call “casualty list” tells us which incumbent will and won’t be running in 2014. Obviously, all of these things can change, and if they do, so will the model’s baseline prediction. Obama’s approval could be lower in 2014, for example. Certainly it is on that trajectory. The number of open seats will also grow. So we treat this only as a preliminary forecast.

At this moment, the model predicts that Democrats will win approximately 48 percent of the national popular vote for the House. The model also predicts that Democrats will win 196 seats, for a loss of 5 seats.

That may seem like a small loss for the Democrats — perhaps “too small,” given the rocky rollout of Obamacare and the loss that the president’s party typically sustains in midterm elections. But there aren’t that many Democratic seats for the taking, thanks to the Republicans’ huge gains in 2010. There are currently 24 seats held by Democrats where Obama received less vote share than his national average in 2012. In 2010, there were 69 such seats.