Up until now, my forecast of the 2018 House midterms has been pretty grim for Democrats. It has noted a 7-8 percentage point Democratic advantage in the generic ballot and calculated a 32% chance of Democrats winning control of the House majority. It has come to that conclusion via a mix of national polls, district-level predictions, and simulations designed to parameterize the error in our measurement. Today, I made an adjustment to that model, and when I ran the computer code it spit out the following:
Admittedly, my forecast for the 2018 House elections looks pretty pessimistic for the Democrats. The media has been quick to pick up on this fact, but they’re glossing over something important: Despite a grim forecast seat share, Democrats have an outside chance of winning the majority — and a landslide election. I talked through this “skew” of expectations in a twitter thread the other day: Let’s talk more about what happens if we’re wrong about the House generic ballot, according to my 2018 model.
It has been roughly two weeks since I launched my forecasting model for the 2018 midterm elections to the House of Representatives. Current generic ballot polling gives Democrats a 7.2 percentage point edge in the national popular vote, roughly where it has been since a month after Donald Trump became president. The forecasting model estimates, contrary to what a 7.2% lead would imply, that Democrats have just a 22% chance of winning the House majority on November 6, 2018.
Note1 This article was written in conjunction with Ryan Matsumoto, a contributor at FiveThirtyEight, Developer Programs Engineer at Google and Stanford Alum. Follow him on Twitter @ryanmatsumoto1. Note2 A previous version of this article had Ossoff up 1.3% with 57% odds. Recent polling data had use revise those estimates to 0.6% and 53%, respectively. In the 2016 Iowa Democratic Primary Hillary Clinton won at least six precincts by way of a coin toss.
You can’t win an election without turning out voters, and boy, are Democrats taking that to heart. Americans in special and primary elections all over the country are turning out for elections at rates unseen in the most recent midterm cycles. We already know that Democrats are overperforming expectations for electoral performance, but raw votes in recent elections offer us some more insight into just how energized their base is.
On Wednesday, May 24th, the Republican candidate for Montana’s at-large congressional district essentially beat (body slammed) a reporter. Then, on Thursday, Greg Gianforte also beat his Democratic opponent Rob Quist in the race for the district’s House seat. Gianforte’s victory cut against some pundits’ expectations of a Democratic pickup — granted, he did break a reporter’s glasses while otherwise being a flawed candidate — and squashed hopes of Democrats being able to flip deep red House seats.