Can Trump Beat the Six-Year Midterm Senate Curse?

Sen. John Thune (R-SD) & Donald Trump

The conventional wisdom about November's elections from most pundits seems to be that the House flipping blue is a foregone conclusion (perhaps even exacerbated by the mid-decade redistricting arms race President Trump insisted upon), but the Senate remains a very steep climb.  This feels accurate on its surface.  Of the competitive races, it does feel like Democrats are in-line to hold all of their current seats (with Michigan or Georgia the toughest hold, but even then Team Blue is in the driver's seat), and that there are true tossups in Maine & North Carolina that, with a blue wave, probably tilt to the Democrats (this past week Republicans got their best recruit of the cycle in the form of Susan Collins running for another term, but even then Collins is in for the toughest environment she's run in since 2008, a cycle she was largely ignored despite the Dems having a good recruit...something that won't be the case in 2026 even if she might arguably have a lesser opponent).

But beyond that, people seem to be operating under the assumption that the Senate contest will not be an even playing field, and that the Republicans seem likely to lose seats, but not their majority.  This is fair-other than Maine & North Carolina, there is no seat on the map that Kamala Harris won by less-than 10-points that the Democrats can target, with the next bluest state (for Harris) being Ohio which she missed by just over 11-points.  This is exacerbated by recent presidential midterms for Donald Trump & Joe Biden where their party actually had a net gain of Senate seats (in 2018 & 2022), with the assumption being that we just don't see swings like that anymore.

However, I want to introduce a new idea here that I don't see discussed a lot, and that's because we haven't really experienced since 2014: the six-year midterm itch.  The second midterm is typically when the public becomes tired of the sitting president-six years of having to endure the same face as a fickle American public results in the American electorate getting restless, and it has historically done some odd things for the president's party in the Senate.

For the sake of this article, we're going to look at the four most recent six-year midterms: 1986 (Reagan), 1998 (Clinton), 2006 (Bush), and 2014 (Obama).  In these cycles, with the sole exception of Clinton (more on that in a second), the president's party got destroyed at the ballot box.  In 1986, the Democrats picked up 8 Senate seats, in 2006 the Democrats won an additional six seats (I'm counting Joe Lieberman as a Democrat here), and in 2014 the Republicans netted 9 seats.  This is a gargantuan turn, and in all three cases, it was worse than what the president endured in the Senate for his first midterm.

This is partially because the Senate, which is a six-year cycle, was anniversarying a really good year for the presidency-the first year that he came into office (and in the case of all but Bush, they came in with landslide victories).  This isn't true for 2026, which is perhaps the biggest nuance here-in 2020, the last time most of this year's senators was up for reelection, Trump lost, and it was a much better cycle for the Democrats.  But the idea that the public is tired of the president was very evident in all but one of these cases: like Trump, Obama & Bush were under-water in their approval ratings, and Reagan had also seen a huge decrease in his popularity.  Again, only Clinton (who had the best approval ratings of the quartet) was popular, and that was reflected in a Senate cycle where 3/5 of the closest Senate races ended up going blue (and the two that didn't involved a deeply unpopular, scandal-prone Senator who nearly won despite that, and a state that was in a transformation into one of the reddest in the nation...that still nearly stayed blue despite polling showing it a likely flip).

I will note that Republicans can feel comfortable to a degree here.  In 1986, eight of the nine Senate races that flipped (all but Maryland) were states that Reagan had won by double digits, but partisanship got in the way more in 2006 and 2014.  In 2006, only one race (Montana) was one Bush had won by double digits the previous cycle, and in 2014 there were none that Obama had won by that margin.  Admittedly, Tennessee in 2006 nearly flipped (and Bush won that by double digits), and in 2014 the problem may have been that there just weren't that many states to begin with that the Republicans might have flipped in this scenario because Obama had won so few of them by double-digits (only six states that went for Obama for double digits were held by Democratic senators in 2014, in part because 2008 had been such a blood bath for the GOP, something that was not the case to the same degree for Trump in 2020).

All of this is to say that we don't know what impact that this will have.  Historically, six-year midterms are rough for the incumbent party, and I think Republicans (or pundits who favor their chances) are taking a bit too much comfort in Trump's impressive turnout in 2024.  I'll close with this-in 2018, a year where Republicans inexplicably picked up two Senate seats, all but one of those seats (Florida, its own universe electorally) were in states that Trump won by 18+ points in 2016.  Do you know what Alaska, Ohio, Maine, Iowa, North Carolina, Texas, & Kansas all have in common?  They're all states with Senate elections this fall...that Donald Trump won by less than 18-points.  Food for thought.