Can Both Parties Make Midterm Gains? Yes.

As 2017 rolls on, 2018 speculation grows. Sure, we just came out of a contentious Presidential election, and sure, there are special elections sprinkled throughout this year, but both parties are keeping their focus on next November, when dozens of Senators face the voters, and a multitude of open Gubernatorial races provide chances for both.

While history shows the Midterms generally favor the out party, the gains are hardly consistent. Going back to Harry Truman’s first midterm, here’s how the White House’s Party performed every four years:

While Presidents Truman and Eisenhower each experienced losses across the board in both of their midterms, it has been a mixed bag for most Presidents since. Johnson, Ford, Carter, and Obama never saw gains or even a draw in Congressional or Gubernatorial races, but Kennedy, Nixon, Reagan, Clinton, and both Bushes did.

One of the more striking cycles is 1986, which featured equal, substantial changes in Senatorial and Gubernatorial outcomes. The Democrats had run through a good period of Gubernatorial contests in the mid 1970s and early 1980s. With many of these incumbents term-limited or retiring, 1986 gave Republicans a chance to make gains. Democrats are remembered for getting the better end of the 1986 deal- the Reagan Revolution’s Class of 1980 was decimated in the 1986 cycle, with 8 out of the 12 members losing re-election.

As we approach 2018, Republicans hold the most Gubernatorial Mansions they’ve enjoyed in decades, and will be forced to defend a lot of open contests: Ohio, Maine, Michigan, Tennessee, Nevada, New Mexico, and Florida to name a few. A few incumbents are up for re-election in Hillary Clinton states as well: Governors Larry Hogan, Charlie Baker, and Bruce Rauner face voters that had rejected Trump by double-digit margins. Two of these three enjoy strong approval ratings and cross-party support, but things can get funny as we approach midterm times. Democrats have relatively few vulnerable races: Connecticut, Minnesota, Colorado, and Pennsylvania all feature open contests or unpopular incumbents.

Democrats enjoyed a really successful 2012 Senatorial cycle, and many of the Senators that had just gotten through it, like Joe Donnelly, Jon Tester, Heidi Heitkamp, and Claire McCaskill, now face electorates that voted for the President by double digits. Joining them are another six Democrats in Trump states, potentially an independent in a state that shifted very hard towards Trump (Angus King in Maine), and one Senator whose state voted for Clinton, but at its most rightward (relative to the nation) in seventy years: Minnesota’s Amy Klobuchar. Republicans have far less territory to defend: Dean Heller’s Nevada voted for Clinton narrowly, but he still has yet to face a challenger, and Jeff Flake’s Arizona voted less Republican last year, but still remains stubbornly red.

For Republicans, a focus on making Senatorial gains is a no brainer. Acquiring a filibuster proof majority is tough and this is the best chance they’ll have in the foreseeable future to pull that off. A lack of really vulnerable seats allows them to focus almost entirely on offense, and even if they fail to hit sixty seats, a larger majority offers some protection from 2020/2022 blow back.

For the Democrats, the Gubernatorial contests, and state legislative seats, are critical for them. The 2020 census, and redistricting, are right around the corner, and Republicans took full advantage the last time to re-draw Congressional and state legislative districts. As they stand now, a failure to win back control of key state governments, like in Ohio, Michigan, Wisconsin, and Florida, would assure a disastrous Congressional map post-’20 that could keep Republicans comfortably in control of the House for years to come.

Both could theoretically win out, but odds are one has a better night and comes closer to their general goal than the other. Ticket-splitting has become increasingly rare, and it’s hard to imagine a November where Senator Sherrod Brown and the Ohio Republican Gubernatorial candidate both lose. Still, such outcomes aren’t nonexistent. Floridians booted their Republican Senator- and replaced their outgoing Democratic Governor with a Republican- in 1986.