Are Republicans going to lose the House in 2018? And if they do, will it be President Trump’s fault?
It’s impossible to know the answer to the first question with any certainty at this point. While major indicators show that Democrats are in good shape for 2018 (polling, incumbent retirements, and election results since 2016 all point in that direction), there’s time for national conditions to improve (or further deteriorate) for the GOP.
But it is possible to get handle on the second question.
Last summer, I found an interesting pattern in the historical polls. During the presidencies of George W. Bush, Bill Clinton, and Barack Obama, the incumbent party often had trouble outpacing presidential approval in generic ballot polls during midterm elections. That’s why the 1994 Democrats, the 2006 Republicans, and the 2010 and 2014 Democrats all had trouble in mid-term House elections—the president was unpopular and many voters didn’t want to support his party (note that 1998 and 2002 are excluded because the aftermath of Monica Lewinsky and the September 11 attacks caused unusual trends in presidential approval).
So is this pattern holding from Trump? Periodically, I like to grab the latest polls and check. (This piece was my last update on the subject.)
This graphic shows polls from RealClearPolitics that measure both presidential approval and the House generic ballot (which asks voters which party’s candidate they’ll vote for in House elections in 2018). Each point is a poll—the vertical location shows the difference between Trump’s approval and support for the House GOP (positive values indicate that Trump has greater support, negative values indicate less), and the horizontal location shows when that poll was in the field.
Most of the points are above zero, indicating Trump’s approval rating is often (but not always) a couple percentage points above what the House GOP gets in the generic ballot.
That’s potentially bad news for the Republicans. Trump’s approval rating is 38.2 percent in the RCP average, 37.7 percent in FiveThirtyEight and 38.8 in the Huffington Post aggregate. If he stays at this level, Republicans will have trouble holding the lower chamber.
But there are some important caveats.
First, Trump’s approval rating could change. Trump has almost a year left before the 2018 midterms—which is more than enough time to improve his approval substantially (or drive it further downwards).
Second, the House GOP’s floor may be higher (and its ceiling lower) than the president’s. In November of 2008, President Bush’s job approval was in the 20s, but Congressional Republicans managed to get 42.6 percent of the House popular vote. By the same token, in November 2002, Bush’s approval rating was in the mid-60s when Republicans held the House with 50 percent of the vote. In other words, there are some voters who will stick with their party even if their opinion of the president changes.
Third, Democrats haven’t yet convinced everyone who disapproves of Trump that they should vote for them. They might. But they haven’t done that yet, so it’s important to track how much support Democrat get in these polls.
Finally, it’s possible that these rules don’t apply to Trump. A historical pattern isn’t a law of nature, and it’s possible that the House GOP will find a way to run ahead of the president.
But for now, Trump is holding Republicans down to a low level in the generic ballot, which should make them nervous heading into 2018.
