Princeton Election Consortium

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OH-12 is ominous for GOP in House…and the Senate

August 7th, 2018, 11:36pm by Sam Wang


At the moment, in the special election in Ohio’s gerrymandered 12th district, Republican Troy Balderson leads Democrat Danny O’Connor by 0.9 percentage point (with 0.6% of the vote going to the Green Party candidate). This is a loss for Democrats, but it’s a 10-point swing from the Clinton-Trump margin in 2016. That’s very much in line with special elections all year, and it has implications for November.

In 46 special elections in 2018, the overall swing from 2016 has averaged 12 points toward Democrats. Hillary Clinton won the national popular vote by a little over 2 percentage points. If this swing were to hold up in November 2018, it would mean a 14-point win in the national House popular vote. I estimate that a 6-point win would be just enough to flip control. A 14-point win is massive, enough for a gain of over 50 seats.

Another piece of evidence points toward a building Democratic wave: Harry Enten of CNN has pointed out that Democratic pollsters are reporting their internal polls far more often than Republican pollsters. This observation corresponds to a minimum gain of 30 seats for Democrats. It’s hard to tell the ceiling because the D/R ratio has not been this high before.

As for the generic Congressional poll? Mostly ignore it. Even in the home stretch it misses some aspect of public opinion, probably because midterm turnout is hard to estimate. However, I will note one thing; it’s currently showing a lead of about 7.5 percentage points for Democrats – much less than implied by the two indicators above. If polls are underestimating election-day Democratic support, any discrepancy is important for close Senate races in Tennessee, Texas, and elsewhere. Recall that Senate polls in 2014 were off: in that case, Republicans overperformed against a Democratic incumbent president. Now the shoe is on the other foot.

What can you do this year? Whether you are a Democrat or a Republican, my advice is the same:

  • Near you, find a competitive House district and get out the vote there. Use the PEC-sponsored district finder!
  • Elsewhere in the country, donate to the most competitive Senate races.¬†I curate these¬†here.

And what if you’re a third-party voter, like the 0.6% who voted for the Green Party in OH-12? I’d say you lack situational awareness of what it means to live in a two-party system. Might be time to rethink that attitude.

Tags: 2018 Election

5 Comments so far ↓

  • LondonYoung

    So, here is another data-driven idea.

    If you look through a table of, say, senate polls on RealClearPolitics you will see a disproportionate number of “blue” leads.
    This makes me think that pollsters’ aren’t “centered” on the most competitive races, but are looking at those favoring the blue team.
    This suggests there are “dark horse” races where the blue team has a real shot but aren’t getting much attention.

  • Amitabh Lath

    Turnout is difficult (impossible?) to model and can change quickly (see 2016, pre/post Comey’s announcement).

    A lot of the “Dems are shoe-ins to take the house” narrative is based on tea leaves and wishful thinking. I don’t blame reporters, boring articles about power of incumbency and midterms skewing old and white probably don’t get many clicks. Democratic steamroller driven by enthusiastic young people is a story you can sell!

    But all it takes is one turnout depressing event. In other words, Republicans are just one early-November thunderstorm away from keeping the house.

    • LondonYoung

      The gambling sites estimate about a 2/3 chance of the dems taking the house.
      I don’t think the shoe-in stories are wishful thinking, they are just the “round to 0 or 100%” tendency that makes for the good stories you mention – and is also reflective of human nature.

      In the spring of 2010 Stu Rothenberg said the GOP had 0% chance of taking the house in the fall. After they did he said that 0% was an accurate estimate at the time.
      What does that even mean?

    • LondonYoung

      Sam’s has now put down his marker at 90% chance the dems take the house.

    • Sam Wang

      Well, I already said it other places. And conditions can change. I’m just saying where I’d put donations if I were in a donatin’ mood.

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