Eh, There have been maybe less than a half dozen times in the last century where the party in power in the White House didn’t lose major seats in a mid-term. And none had a president this unpopular.
I think 1934, after 9/11, 98 with Clinton and maybe 1 or 2 more.
I think where this stuff may bite them is in 2020. Democrats seem to respond much more to positive, idealistic campaigning over negativity and fear like Trump thrives with. And not sure I see anyone fitting that well. It will once again be a battle of mobilization in key states, and Trump only needs to lose or have sit home a few people out of every 100 Trump supporters in key states, or a few more Democrats show up in key states to win it. So the challenge isn’t great but it’s there.
Though I guess I kind of see Trumps presidency much differentally. On the campaign trail he made populist economic appeals and overtures, as president he has basically abandoned that for his own identity politics and focused heavily on culture wars issues, from players kneeling, to Charlottesville, to picking fights with the Ball family, to the news today about the 200,000 Salvadorans. And he will no longer have the blank slate, write-your-own-adventure advantage. His Justice Department is taking a hard stand on marijuana, that even a majority of Republicans are against. He just had the net neutrality fiasco, failed to improve healthcare, the Puerto Rico disaster that ironically feeds more angry voters into a major swing state, and it will be ridiculously easy to hit his administration with charges of rampant cronyism.