Wednesday, November 08, 2017
"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 tossup races go a certain way, and when the party winning those tossup 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 instead1, 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.
To put it another way, Tuesday’s results shouldn’t have exceeded your expectations for Democrats by all that much because you should have had high expectations already. Midterm elections — and usually also off-year and special elections — almost always go well for the opposition party, and they’re going to go especially well when the president has a sub-40 approval rating.
So, does that mean that Democrats are clear favorites to pick up the House next year? No, not necessarily. I’d say they’re favorites, but not particularly heavy ones. Democrats face one major disadvantage, and have one major source of uncertainty.
The uncertainty is time: there’s still a year to go until the midterms. This could cut either way, of course. The political environment often deteriorates for the president’s party during his second year in office, and one can imagine a variety of factors (from attempting to pass an unpopular tax plan to ongoing bombshells in the Russia investigation) that could further worsen conditions for Republicans. One can also imagine a variety of factors that would help the GOP: Democrats overplaying their hand on impeachment; a rally-around-the-flag effect after a war or terror attack; Trump quitting Twitter. (Okay, probably not that last one.) That Trump is so unpopular so soon in his term makes all of this harder to predict because there aren’t any good precedents for a president with such a poor approval rating so early on.
Democrats also face a big disadvantage in the way their voters are distributed across Congressional districts, as a result of both gerrymandering and geographic self-sorting. Although these calculations can vary based on the incumbency advantage and other factors, my back-of-the-envelope math suggests that Democrats would only be about even-money to claim the House even if they won the popular vote for the House by 7 percentage points next year. The Republican ship is built to take on a lot of water, although it would almost certainly capsize if the Democratic advantage in the House popular vote stretched into the double digits, as it stands now in some Congressional preference polls.
Nonetheless, my sense is that the conventional wisdom has, to this point, somewhat underrated the Democrats’ chances of having a wave election next year. And it’s for some fairly stupid (although understandable) reasons..."
The Fundamentals Favor Democrats in 2018 | FiveThirtyEight