Sizing Up the 2018 Gubernatorial Map

Sizing Up the 2018 Gubernatorial Map
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Over the past few weeks, we’ve established that the 2018 Senate map is worrisome for Democrats, but what about the gubernatorial map? An enormous number of the country’s laws are made at the state level and, perhaps more significantly, many of the governors elected in 2018 will have a say in the next round of congressional redistricting. That gives Democrats, who have a low level of power in the states and sometimes assert that gerrymandering is at the heart of their minority status in the House, a big incentive to invest in these races.

And right now, many on the left seem optimistic about their prospects. A number of Republican governors in key states are retiring or will be termed-out, and some GOP incumbents are defending swing or blue states. Democrats are only defending a few seats, none of which are in truly red states. Moreover, Democrats are hoping that national conditions will be favorable in November 2018, allowing them to regain states Republicans won in 2010 and 2014.

While it’s too early to know exactly what the conditions will look like next year or how these elections will turn out, it’s possible to dig deeper into the data and get a better idea of exactly how promising this map is for Democrats.

The Democrats Have a Good Map

The top-line numbers -- how many Republicans are retiring, which states they’re retiring in, etc. -- are positive for the Democrats. There are multiple ways to display this data, but my preferred method looks like this:

This graphic shows the partisan lean of every state (each of which is represented by a dot; the procedure for calculating partisan lean is detailed here) with a Republican governor heading into each election from 1986 to 2018. Right-leaning states are located above the black vertical line; left-leaning states are below it; and a black outline indicates that an incumbent is running. I assumed that all eligible governors would run for re-election in 2018 unless they have stated otherwise (this might not end up being true, but it’s a useful approximation). The basic idea is to show how much ground the Republicans have had to defend in the past, compare it to 2018 and note incumbency (since incumbents enjoy various advantages).

The current distribution of dots bears closest resemblance to 2014 and 1998, elections that, uncoincidentally, also occurred four years after a Republican wave. Any party that makes big gains in one election will have more exposure to loss when those seats are up again. But unlike the 2014 and 1998 GOP, 2018 Republicans are coming off two consecutive waves -- meaning that a number of the governors elected in 2010 and re-elected in 2014 cannot run again. About half of the 26 Republican-held states that are up in 2018 will not feature an incumbent. That’s a contrast with 2014, when only three of the 24 Republican governors retired or were term-limited, and with 1998, when 18 out of the 25 GOP-held states featured incumbents running for re-election.

Some of these retiring or ineligible Republicans are leaving key states with open contests. Florida, Maine, Michigan, Ohio and Nevada could be classified as swing states (or states that lean slightly toward one party), and all of their Republican governors are termed out or retiring. But some open states such as Idaho, Wyoming, South Dakota, Oklahoma and Tennessee are highly conservative and will likely be receptive only to Democrats who have distanced themselves from the party’s national brand.

Democrats might also target some incumbent Republicans in deep-blue states. A Morning Consult poll shows that Illinois Gov. Bruce Rauner’s approval rating is underwater, and Sabato’s Crystal Ball rates the race as a toss-up. But some of the other Republican incumbents in typically blue states might be tougher to topple. Govs. Larry Hogan of Maryland (pictured), Phil Scott of Vermont and Charlie Baker of Massachusetts are all near the top of Morning Consult’s list of most popular governors. While those high approval ratings don’t always translate perfectly into general election support, these governors might fare better than a generic Republican would -- suggesting that some of the best Democratic pickup opportunities are outside the country’s bluest region.

So far I’ve mostly laid out the landscape for Democratic gains. That’s because there isn’t much to see from the GOP perspective. This graphic encapsulates the issue:

The partisan lean is the same measure as described above, but this graphic isolates seats held by Democrats. In 2018, Democrats will be defending very few seats, and they’re mostly in highly Democratic states. Republicans have an opportunity in still-Democratic but red-trending Minnesota, an open seat that Crystal Ball rates as a toss-up. The unpopularity of outgoing Gov. Dan Malloy might drag Connecticut Democrats down in the same way that Gov. Sam Brownback might hurt Republicans in Kansas. But Democrats are enjoying the silver lining of losing a large number of seats in the last two midterms -- they don’t have to defend as many governorships as Republicans do.

But a Good Gubernatorial Map Is Worth Less Than a Good Senate Map  

That being said, a good gubernatorial map isn’t worth as much as a good Senate or House map. Gubernatorial races have historically depended far more on the candidates and state-level conditions than congressional races do, where presidential approval and public opinion on national-level events often dominate.

In fact, partisanship only recently became a helpful predictor of gubernatorial results. Just compare the relationship between partisanship and results in 2010 and 2006.

In 2010, the overall political leanings of a state was a reasonably good predictor of the final results. Partisan lean doesn’t explain everything that’s going on in this graphic (e.g. Colorado is an outlier because of a problematic Republican candidate and a third-party contender), but it certainly seems to be capturing something. There was a decent relationship between our measure of statewide partisan lean and final results in 2014 as well.

But in 2006 and some prior midterms, the relationship was weak or nonexistent. Governors, unlike members of Congress, don’t vote directly on the president’s agenda and were often able to craft their own brand and platform based on management competence and state-level issues. In many cycles prior to 2006, incumbency had a statistically significant effect on the results but state-level partisan leanings didn’t.

It’s impossible to tell ahead of time exactly how well traditional measures of partisanship will predict the results of the 2018 gubernatorial races. It might be an orderly relationship, as it was in 2010, or it could be closer to the mayhem of 2006. The increasing strength of partisanship on all levels of politics makes a 2006-style scatter less than likely, but the point is clear -- the map tends to exert less influence on gubernatorial elections than it does on other key state and national-level races.

And again, it’s impossible to know what the national-level conditions will look like in a year and a half. But this map, insofar as it influences the results, seems to be a bright spot for Democrats.

David Byler is an elections analyst for RealClearPolitics. He can be reached at Follow him on Twitter @davidbylerRCP.

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