Can The Dems Take The House in 2018? An Analytic Look

Tom weighs in with our first serious look at the 2018 House midterms.

Here is the headline:  the House of Representatives is there for the taking by the Dems in 2018…but, even if the political environment on Election Day, 2018 is similar to today, that is, wildly skewed in favor of the Democrats, it is going to be a close call.

What would it mean if the Dems re-took the House?  It’s hard to understate the magnitude of such a coup.  The Trump agenda would stop dead in its tracks.  Nancy Pelosi would control what bills came to the House floor.  Assuming the GOP held the Senate (which is likely), any proposed GOP Senate legislation would face only a dim prospect of securing Democratic support in the House to ever reach Trump’s desk for signature.

And, the House could begin impeachment proceedings.  The charges may not carry through to a Senate conviction – 67 Senate votes would be required, which would mean, say, 16 to 22 GOP votes.  But the showdown could be put in motion and debated for months on end, with little oxygen left for anything else.  To be clear, Democrats seem divided on the prospect of impeaching Trump, fearing “overreach,” Senate conviction failure and a backlash.  The rising sentiment is that Mueller needs to come up with a clear smoking gun for the Dems to move, something convincing that will attract GOP support.  Otherwise, the prospect of running against Trump in 2020 has far greater appeal than impeachment without conviction.

If the Dems took the House but the GOP held the Senate, Trump would have only one clear area that he could affect without meaningful interference:  he could continue his dramatic reshaping of the judiciary.  Only 51 Senate votes (including Pence, as needed) are required to approve a judge, even a Supreme Court justice, and the House is not involved in this process.  But Pelosi could stop the rest of Trumpworld legislation, or negotiate hard for Dem-friendly terms.

THE CURRENT PLAYING FIELD

Currently the GOP holds 241 House seats to the Dems’ 194.  To maintain control of the House, the GOP can afford to lose no more than 23 seats; if they lost exactly 23, Paul Ryan would still preside over the House with a 218-217 margin.

RECENT HISTORY

The best way to understand the current environment – essentially, the electoral mood -- is by analogy, using recent history as our guide.

It is conventional wisdom that first-term Presidents have a tough time in their first mid-terms.  Translating campaign poetry into governing prose is difficult work, and time and again the bloom comes off the rose reasonably quickly.  George W. Bush 43 was one of only two first-term presidents in the past 100 years to see his party pick up seats in the midterms, the other being FDR in 1934.  The GOP gained seats under Bush 43 on the strength of strong positive feelings about him (and his party) in the aftermath of 9/11, which had occurred 14 months earlier. 

This chart shows the last seven mid-term elections under first-term presidents, with a set of data that describes the political environment, with the key data being the president’s approval rating and the closely linked “generic ballot.”  The generic ballot is a polling question that asks which party the respondent would support in a congressional election – no candidate is specified, and that is what makes it “generic.”

The generic ballot is exceptionally predictive of mid-term outcomes.  In each year, if the generic ballot was negative for the president’s party, which it was in six of the seven elections, that party lost ground.  The one time it was positive was when Bush 43 gained his 8 seats.

Year	President	Pres Party House Seats	Pres Approval Gallup Pre-Election	Pres Party Gallup Generic Ballot Net	Actual Pres Party Seat Change	BTRTN Model Pres Party Seat Change
2010	Obama	257	45	-9	-63	-64
2002	Bush 43	221	63	6	8	6
1994	Clinton	258	46	-7	-54	-57
1990	Bush 41	167	58	-8	-8	-6
1982	Reagan	192	42	-10	-26	-24
1978	Carter	292	49	10	-15	-13
1970	Nixon	192	58	-6	-12	-10

Another correlation is worth noting:  the magnitude of the change is related to how many seats the party in power is holding.  Bill Clinton and Barack Obama had huge majorities at mid-term time (258 and 257 Democratic seats, respectively), and that in combination with those negative generic ballots translated into huge losses, 54 seats for Clinton and 63 for Obama.  On the other hand, Ronald Reagan and George H. W. Bush also had large negative generic ballots, but the GOP held far fewer seats, 192 under Reagan and 167 under Bush, so they lost only 26 and 8 seats, respectively.  This makes sense – the fewer seats you have, the greater percentage of them are solid seats, which provides a floor on your losses.

What does all this mean for Donald Trump?  Trump’s current profile – just over 10 months from the mid-terms – closely resembles that of Clinton and Obama (see a subset of the chart, below).  His party is firmly in control with 241 seats, like Clinton (258) and Obama (257).  He himself has a wretched approval rating, (using Gallup, for consistency with past presidents’ data) at 38%, well below even the low levels that Obama (45%) and Clinton (46%) held at the time of their midterms. 

And Trump’s generic ballot is extremely negative, more negative than even that in Clinton’s time (-7) or Obama’s (-9).   There have been a slew of generic ballot measures of late 15 in the month of December), and on average the Dems hold a breathtaking +11 point lead over the GOP (and the one poll that was done after the tax bill was signed showed only a +1 point improvement for the GOP).

		Pres Party House Seats	Pres Approval Gallup Pre-Election	Pres Party Gallup Generic Ballot Net	Pres Party Seat Change
Year	President
2018	Trump	241	35	-11	?
2010	Obama	257	45	-9	-63
1994	Clinton	258	46	-7	-54

THE MODEL

So the question is, given this environment, if it was similar next November, how many seats might the GOP lose in 2018?

BTRTN built a regression model using all off-year House elections since 1970, the first year we had all the relevant data.  The model predicts, specifically, the number of seats the President’s party will win or lose in an off-year election.  There are five variables in the model:  the president’s term, the president’s party, the generic ballot, which party is in the majority, and the number of seats held by the president’s party.

The model provides an extremely tight fit with actual results, as you can see by the chart below; the prediction is within two seats of the actual outcome in each of the last six first-term president mid-terms.

		Pres Party House Seats	Pres Approval Gallup Pre-Election	Pres Party Gallup Generic Ballot Net	Actual Pres Party Seat Change	BTRTN Model Pres Party Seat Change
Year	President
2010	Obama	257	45	-9	-63	-64
1994	Clinton	258	46	-7	-54	-57
1990	Bush	167	58	-8	-8	-6
1982	Reagan	192	42	-10	-26	-24
1978	Carter	292	49	10	-15	-13
1970	Nixon	192	58	-6	-12	-10

Given that Trump is a first-term Republican, the GOP is the majority part with 241 seats, and the generic ballot is Dems +11, the model predicts the GOP will lose a whopping 61 seats in 2018 if the generic ballot remains in this range.

But that is not the final answer.  We have to make an adjustment based on the impact of a more recent factor:  gerrymandering.

THE ADJUSTMENT

In 2016, despite the election of Donald Trump, the Dems made progress in the House, albeit modest.  They picked up a grand total of +6 seats.  What is astonishing about this is that, overall, the GOP won the “popular vote” in the House (that is, the sum of all the individual 435 elections) by a 49%/48% margin, yet they came away with a 55%/45% share of the seats. Thus the GOP came away with a far greater number of seats than they “deserved”; such is the effect of the epidemic of gerrymandering now in action.  A one-point gap might have more reasonably translated into a 220-215 House composition, or a +5 GOP seat lead instead of the +47 they enjoy.

Since 2010, the GOP has done an astonishing job of winning state houses and controlling state Senates and Assemblies, and thereby effecting redistricting schemes that favor their candidates (a.k.a., “gerrymandering”, named after Founding Father Elbridge Gerry who, as Governor of Massachusetts in 1812, signed a bill authorizing redistricting that favored his party, including a district that was thusly shaped much like a salamander, resulting in the portmanteau -- “gerry-mander” -- that is still in use today).

You can see from the chart below that in 2010, when a relatively unpopular Barack Obama got crushed in his first mid-terms, there were 82 “close” elections – elections decided by a margin of 10 or fewer percentage points – which was just under 20% of all the races.  But that number of close elections has steadily dwindled, and in the last go-round in 2016, there were only 35 such races – 8%. Clearly gerrymandering is a factor.

	House Elections Decided  By 10 Points or Less
Year	#	%
2010	82	19%
2012	68	16%
2014	51	12%
2016	35	8%

The GOP won only 17 races by 10 percentage points or less in 2016, which means that even if the Dems flipped all of them in 2018, that would not be enough to gain control (as mentioned, they need to flip at least 24).  There are another 18 races by the GOP lost by 11 to 15 percentage points, and the Dems would have to take more than a few of those as well.

A simple adjustment would be to say that the number of elections “in play” is probably roughly half of what it was back in 2010, the last time we had a first-term president at mid-term time.  That would turn the model’s +61 Dem “wave” into somewhere around +30, still enough for the Dems to retake the House, but with some Election Night nail biting.  In fact, if it gets much closer than that, we may not know who controls the House for days or weeks.  (We might be getting a preview of that in the battle for the Virginia legislature, which is still in dispute over a month after the election.)

The takeaway from this exercise is three-fold:  1) if this political environment persists, the Dems have a solid shot of re-taking the House; 2)  keep a close eye on the “generic ballot” which is the strongest predictor of actual performance, adjusted for gerrymandering effects (anything north of a +6 Dem lead in the generic ballot will likely put the House in play); and 3) at the end of the day, elections are still won and lost based on the popularity of incumbents (and whether they choose to run again – 24 GOP reps are not, versus only 14 Dems so far), the strength of the challengers and the effectiveness of their campaigns.  Don’t take any of that for granted. If the Dems want to re-take the House, they have to replicate what they have done in the high-profile New Jersey, Virginia and Alabama wins in 2017, and bring that same level of talent, resource, commitment and energy to a national scale in 2018.

We’ll see if the tax cut breakthrough provides some momentum to the GOP to prevent a Dem wave in 2018.  But keep in mind that the bill gets very low marks – polling shows only 1/3 of Americans favor the law, while over half oppose it.  And we’ll see what else Trump and the GOP can accomplish in 2018, when their Senate margin narrows to 51/49.