The Fundamentals Favor Democrats In 2018

[Amica Nostra 4,803]

https://fivethirtyeight.com/features/the-fundamentals-favor-democrats-in-2018/

Democrats had a really good night on Tuesday, easily claiming the Virginia and New Jersey gubernatorial races, flipping control of the Washington state Senate and possibly also the Virginia House of Delegates, passing a ballot measure in Maine that will expand Medicaid in the state, winning a variety of mayoral elections around the country, and gaining control of key county executive seats in suburban New York.

They also got pretty much exactly the results you’d expect when opposing a Republican president with a 38 percent approval rating.

That’s not to downplay Democrats’ accomplishments. Democrats’ results were consistent enough, and their margins were large enough, that Tuesday’s elections had a wave-like feel. That includes how they performed in Virginia, where Ralph Northam won by considerably more than polls projected. When almost all the toss-up races go a certain way, and when the party winning those toss-up races also accomplishes certain things that were thought to be extreme long shots (such as possibly winning the Virginia House of Delegates), it’s almost certainly a reflection of the national environment.

But we didn’t need Tuesday night to prove that the national environment was good for Democrats; there was plenty of evidence for it already. In no particular order of importance:

• President Trump’s approval rating is only 37.6 percent.
• Democrats lead by approximately 10 points on the generic Congressional ballot.
• Republican incumbents are retiring at a rapid pace; there were two retirements (from New Jersey Rep. Frank LoBiondo and Texas Rep. Ted Poe) on Tuesday alone.
• Democrats are recruiting astonishing numbers of candidates for Congress.
• Democrats have performed well overall in special elections to the U.S. Congress, relative to the partisanship of those districts; they’ve also performed well in special elections to state legislatures.
• The opposition party almost always gains ground at midterm elections. This is one of the most durable empirical rules of American politics.

So while Northam’s 9-point margin of victory was a surprise based on the polls, which had projected him to win by roughly 3 points instead,¹ it was right in line with what you might expect based on these “fundamental” factors. For instance, a simple model we developed based on the generic ballot and state partisanship forecasted a 9-point win for Democrats in Virginia and a 13-point win in New Jersey, pretty much matching their actual results in each state.