So the election is over and your party now holds the coveted legislative/executive trifecta. Congratulations! But wait, some in the legislature are still butt hurt that their horse isn't in the executive stable. What will they do? What WILL they do?
Why, switch sides of course. Notwithstanding the Dems avowed intent to abolish the filibuster to put President Clintons judges on the supreme court, several highly placed Republicans are prepared to leave it in place to prevent Trump from getting his appointments seated. This could presumably be extended to any of Trumps policies requiring legislation. This is the sort of get along, go along behavior that culminated in Trumps election in the first place.
I suppose we're now officially a 3-party country; The Socialists on the left, calling themselves Democrats, The Capitalists on the right, calling themselves Republicans, and a center-left party supporting taxes and regulation masquerading as Republicans straddling the center.
To quote a famous Italian: "Nothing is more difficult than to establish a new order of things."