There is only way to defeat Trump...a paradigmal shift in both Party and Person...aka "Run Johnny Run...as a Democrat"...and being able to do so legitimately "with absolutely no guilt or remorse" and without formally and pro-actively leaving/abandoning the GOP.
Trump has a lock on his "Base" (that 30% or so of the American voting public) and like a python grabbing onto its prey, continues to coil evermore around it, leaving it for the most part inescapable...and unreachable.
People say "Hey why does Trump only focus on "The Base"?"..."Is he stupid?"..."Why does he just keep feeding it red meat...and driving Independents away?"... "Doesn't he realize he can't win a second term with only "The Base?".
On the last Q, Trump knows that better than anyone he can't, and why he's not being ignorant to the big picture...that he definitively needs more than his base to win in 2020. The point is that "Pythoning" his base is not his endgame...it is but Phase 1 of a broader what I'll coin 2 Phase "Bannon/Stone 2020" Re-Election Strategy...Roger Stone being the widely recognized real brains behind the creation of Trump and both Bannon and he the fuel to since sustain him.
Note: If you think Trump and Bannon are not still very close and collaborating, you probably believe Trump drained the swamp..."and its empty"...and he loathes gators. Too, regardless of what happens to or with Stone in the Mueller investigation, he still like Bannon, will be "available to Trump"...just a phone call away"and Trump needs both...like a cripple does a pair of crutches.
Phase 1 being in essence to inoculate "The Base" from any GOP'er who wants to challenge him, since any GOP'er considering such a run as a Republican knows that without "Trump's Core 30...The Base", no individual "GOP'er" can beat him...so why run a campaign doomed to failure from the get go (ie Trump will have no challengers...so "Bannon/Stone 2020" Phase 1 becomes a big success).
On the Democratic side, the combination of 1) "WAY LEFT liberal wing bias/direction" (using the metaphor of a football field, the Democrats are (really) deep in their own "red zone"...call it their 5 yard line and trending towards the 1 yard line) and the enormous selfish fratricidal "Berniecrats" infighting (Sanders/Warren/Harris/Gilibrand/Booker/Cuomo"Clinton? (don't count her out to throw her hat in the ring...aggressively...the Clinton's need to have a campaign in their life to function"they will not like the good old soldier Gen Douglas McArthur, "just fade away"...and she now ironically is in a 2015 Trump-like position competing against 10-15 others (and everyone dismissed him back them) who will dilute and null each other out...while detestable by many, she still can outlast any single other opponent...and she's selfishly thinking (before the 'Kasich factor" as follows) "three's the charm") and the "if" you can argue to separate him from that socialist crowd, the anti-populism gaffe driven geriatric Biden and his own Trump-like bombastic buffoonery, coupled with 2) NO "appealing to the masses core party messaging".
They (the Berniecrats or Biden Anti-Populists...and to be clear the left wing Bernie/Warren Dems will ultimately push out Biden"as the Berniecrats increasingly control/rule the party"and the Berniecrats being pressured by the emerging "even lefter" young Ocasio-Cortez liberals) won't (can't) win on a consistent pure anti-Trump themed messaging campaign...which seems all they have), leaves Trump in great position to complete and declare Phase 1 a success around mid 2019 when its clearly way too late for any Republican to mount a feasible challenge to him, even under the best of circumstances. He then shifts to Bannon/Stone 2020 Phase 2...securing both Independents and the conservative/moderate Democrats (who hate "Berniecrats" and Ocasio-Cortez liberals).
And just to further underscore that Democratic Party swing to "HARD LEFT", and growing rebellion, and yet another reason for Kasich to "take the (vacated/abandoned) middle...as a Dem", is the absolutely stunning jaw dropping massive defeat of the ten term 4 th ranking House Democrat Joe Crowley by a previously unknown 28 year old millennial liberal, Alexandria Ocasio-Cortez.
Phase 2 being a mild moderate swing (and slightly softened bombastic buffoonery and maybe even mixing in a few truths) to the middle (center left/center right (ie the 25 yard line to midfielders on both sides) to woo back "a good chunk" of the Independents Trump lost through his "narcissistic pathological lying nonsense et al" the first 2.5-3 years of his presidency, and too conservative/moderate Democrats who may personally dislike (even despise) Trump but certainly do enjoy some of his policy accomplishments, most notably tax credit windfalls (at the expense of future generations...these tax cuts (without offsetting entitlement reform) just accelerate the US debt driving towards insolvency) and a booming economy, which they see being taken away by the "Sanders/Warren" Ocasio-Cortez" socialism principled Presidential Democratic candidate.
There is also a group of younger Democrats uneasy about the party drifting too far left.
Representative Cedric Richmond of Louisiana said he understood that Democratic voters were "furious and scared at the same time," but he also said he wished his party had a moderating influence to counter Senator Bernie Sanders of Vermont, the democratic socialist who has been at the front end of the party's turn left.
"Bernie is fighting for his principles on what direction the party should go," he said, "but we don't really have anybody doing it on behalf of moderates and other Democrats. It has become a one-sided conversation."