There are two elements I think being overlooked here. I completely agree that the Republican party is riding Trump hard to get what they want, but that strategy is just about played out, and they're stuck with him and his pathological need to play to his base. During this period the Republican base is getting Trumpier, but smaller. See the 2018 results.
The two elements being missed, though, are the fragility of the economy
as a result of his (and their) policies, and the energy the much younger and diverse Democratic field is generating. As to the first - the economy hasn't really ticked up, but maintained the trajectory of Obama's terms. It is more volatile (and vulnerable) now because of the tariffs tiffs. Foreign actors can manipulate the economy, short term (like at election time) by imposing new duties at just the right time. Moreover, it is a significant drag on major export markets like agriculture, manufacturing (See, Boeing), and services that depend on exports for revenue. There are already signs of slowing and a good chance of recession before 2020.
CNBC. Also, the tax cuts are driving up the deficit and most taxpayers ended up with less or no refund this year (next year will be worse).
As to the second, consider the diversity and youth of the freshman class in the House. They got there because they tapped into a new energy of the youth vote, and demographic changes are accelerating this cycle. (
Gen X and millennial are replacing boomers.) Although the Democratic field is large, I think Dem voters will coalesce behind whomever the nominee is in the end. They did it for Hillary even though she was not compelling, and they're more motivated, now. Trump's victory was a fluke - 87,000 votes, but those States have already turned bluer. Wisconsin and Pennsylvania now have Democratic governors. Moreover, the elections of 2018 showed that Democrats aren't sitting on their hands.
I'm not saying it Trump can't win. Electoral college dynamics favor the Republican candidate (See Bush 2000 and Trump 2016). But Democrats are hungry and Republicans are older and whiter than ever before. The bigger fight will be the Senate, but that also favors change.
