This is more likely than most think.
I'm mostly convinced Trump is a one-termer since the economy is most likely going to have a downturn before Oct. 2020, and that plus Trump's insanity/incompetence will doom him.
I think the GOP is going to be very, very demoralized until Trump leaves. Then I can foresee a kind of Tea Party 2.0 that spends all of 2021-24 clawing away and attacking whoever the Democratic President is.
I also think we're more likely to see one-termers now, since I believe with social media and the decreased relevance of campaign cash, the main advantages of presidential incumbency will decline
Agreed
But incumbency hasn't been this strong since JQ!