N.H. House forecast model projects Democrats poised to retake majority
Our 2016 forecast model projecting the partisan outcome for the New Hampshire House indicates Democrats are likely to hold the majority after the dust settles on the 2016 election.
If the election were held today, our updated model predicts Democrats would win 222 seats to 178 for Republicans, almost exactly the same margin we projected in July when we rolled out this year’s model.
We have, however, made one significant change in methodology since we took our first look at the election. Rather than use polling averages for the presidential race as our polling baseline, we’re now using congressional generic ballot surveys.
As before, we aggregate the polling averages from Huffington Post, which currently has Democrats leading Republicans by a 5.8 percent margin; Real Clear Politics, which gives Democrats a 4.3 percent advantage and Talking Points Memo, which has Democrats up by 5.2 percent.
The reason for this change in methodology is the potential for an increase in split ticket voting, particularly among Republicans who may support down-ballot Republicans but not cast a vote for Donald Trump.
Split ticket voting in general has declined dramatically over the last half-century. In 1972, for example, 193 House districts out of 435 (44%) choose one party’s presidential nominee and the other party’s candidate for Congress. By 2012, the analysis of district-level election results by Pew Research found only 26 House districts (6%) split their vote in the same way.
There’s some evidence, however, that we may see an increase in ticket splitting this year. FiveThirtyEight, for example, has noted that as Clinton increased her polling lead after the first presidential debate in late September, Democratic Senate candidates did not see similar gains.
Similarly, the most recent New Hampshire polling from the UNH Survey Center found Hillary Clinton leading Trump by 15 points, a significantly larger margin than the leads UNH measured for Democratic candidates for the U.S. Senate and for governor.
As we approach election day, we’ll begin updating our model each day. You can track the changes in the graph on the right.