To share/steal an analogy I heard that I found amusing on this subject:
The impeachment is kind've like if America's political parties were watching entirely different movies. Republicans are watching Hoover, and noting how this is all a tale of insider government intrigues and abuses targeting their guy out of misaimed and perhaps outright corrupt aims on the part of the FBI and partisan folks associated. Democrats are watching Frost/Nixon, they're engaged in a dramatic and stirring tale of oversight of a corrupt and fiendish president who is making a mockery of the process and Washington...Except the soundtrack to Frost/Nixon has been replaced with a loop of Yakety-sax (with why that is so debatable between 'Dem missteps' and 'Republican/Trump clownery' depending on your partisan position, I suppose).
Greens are, of course, still watching Fern Gully. And Libertarians are watching Firefly.
Again. They don't really care, and neither do a large number of other Americans who are watching
something by Disney in this holiday season and don't have time for government because the Mouse has them by the balls.
(Credit for the above belongs to show-host Andrew Heaton)
- Trump appeared scary. A day did not go by that some mainstream media piece didn't publish something about social disorder from riots over his victory, supposed treason via the Russian Probe, the rise of white racists via Charlottesville, alleged sexual affairs in regards to Stormy Daniels (which built off his hot mic from 2016 and supposed sexual assaults), constantly launching verbal attacks on NATO members, launching two missile strikes in Syria (which supposedly would put us at war with the Russians--the very people he's apparently a puppet of), nuclear escalation by threatening to tear up the Iran Nuclear Deal, and a literal nuclear pissing match with the leader of North Korea, which lead to actual naval deployments and nuclear test missiles being fired over Japan.
- Trump appeared incompetent. Within the first two years of his presidency, his entire administration was leaking--most of which were easily discredited rumors (though they were given major headlines in every news agency broadcast), but gave the appearance of unprofessional control. Said leaks also insisted on corruption and incompetence within the administration. Which was then followed by numerous dismissals and resignations over the next two years, ranging from lower level civil servants and appointments to big names.
- ACA reform failed in the Republican House and Senate. Repeatedly. The Reform was heavily expected by the Midlanders and Yankees, who had hoped that Trump would provide them with a comprehensive, affordable health insurance system as opposed to the one that Obama had given them.
- Various Republican sex scandals coming to light during 2017.
- Very contentious SCOTUS appointments.
I'd add to this with:
6. Economic concerns and fears of recession at a regular interval (though perhaps this falls under number 1).
7. Trump is a blowhard, narcissistic, East-coast asshole who fundamentally disconnects with the culture/outlook of a good number of folks (even those inside his voting bloc or, if you wish to use it, the American nations--the South and West tending to have degrees of courtesy-culture Trump flagrantly disregards), and associating Republicans with him ineviteably drove people (prominently those in suburbs who are middle to upper-middle and thus also more disposed towards courtest-culture) away the same way Dems associated with Obama got driven out in 2010. See the recent flare-up over his stuff on Dingell as the most recent instance of this type of thing.
8. Democrat candidates weren't associated with, nor for the most part were they, all that far-left and featured prominent veterans and moderates who could appeal to the suburbanite/courteous sectors that Trump and Company alienated.
Seven is, of course, locked-in as a permanent factor of Trump because...Trump. Six has gradually eased off as growth and stability has solidified confidence much more. And eight is...remaining to be seen, but this impeachment stuff doesn't help (especially if it's current status of being low on people's list of concerns and not even attracting universal partisan support continues).