Impeachment is not going to happen. A Constitutional crisis is not going to happen. Both of these things require the Republican party - or at least parts of it - to commit political suicide by materially opposing Trump.
Every Republican watched the primary and general election campaigns. They watched every candidate fail against Trump by wide margins. Even Ted Cruz, who was an insurgent Tea Party candidate five years ago, failed against Trump.
Make no mistake. It is not merely because Trump is not a current politician. Carly Fiorina and Ben Carson both fit that bill and failed miserably. What Trump offered was a promise to use extraordinary executive powers to excise America of non-white people and to cut the police at all levels of government (as well as freelance vigilantes) more slack in doing the same.
Trump has largely delivered on this promise.
In his first week of governing, he already had over 200 people locked up for protesting his inauguration, an executive ban on US immigration from majority Muslim countries, and border patrols across the country setting up impromptu highway checkpoints. He has been consistently pushing through a bevy of executive orders, however redundant or symbolic, much to the delight of Republicans who have consistently given him a job approval rating above 80%. As far as Trump supporters are concerned, he has been fighting to do what he said he would.
I regret to inform you that it's time for some game theory.
Republican lawmakers can see the writing on the wall. Their polling has not been so charitable, and their successes are little to brag about. As the self-described Freedom Caucus tries to pass market-oriented reforms, scions of the AltRight are derisively sneering, "Muh freedom!" While Democrats presumptuously gloat about the threat of the 2018 general election, sitting Republican lawmakers see the threat of the primary.
If the Tea Party could do it, why not the AltRight?
But let's say there were a sufficient number of Republicans who felt insulated against a Trumpist insurgency to call impeachment proceedings or (somehow) a Constitutional Convention. Strategically, the GOP as a party would not want to risk creating momentum for Democrats who would likely lead such a campaign.
For now, the Democrats can secure no material power without Republicans attempting to seize power from Trump. As long as Trump remains in higher esteem than Republican leadership among the Republican base, any attempt at Trump's power is political suicide for individual party members as well as the GOP itself.
The Democrats, for their part, seem satisfied in their position as complainant. At every available opportunity, Democratic leadership has thwarted the insurgent social democratic wave that followed the Sanders campaign. Once again, the DNC is banking on the obligation vote with told-you-so tactics. There is little reason to believe that it will work this time.
In such an unseemly equilibrium, Trump will continue to accumulate executive power through an evolving roster of unqualified provisional directors and secretaries who will rubber stamp his directives on command. Apart from the occasional symbolic rebuke from Democratic leadership, Trump will face little in the way of material opposition as grassroots resistance continues to be chastized for blocking highways and punching Nazis.