He is used to bullying and insulting fellow Republicans to get his way. Like Clinton, he will suddenly find his ability to push his own party—either on political or policy questions—is deeply limited. Senate Majority Leader Mitch McConnell has already signaled to Trump that he needs to put a sock in it when it comes to criticizing GOP senators.
The reality is that many Washington conservatives dislike Trump as much as Democrats do but are afraid to break with him publicly. These conservatives must ask the cost for their principles. Many conservatives sincerely believe their rhetoric about the need for a strong presidency unshackled from excessive congressional and judicial impediments. People like Dick Cheney and John Yoo face an awkward question: Is this what you had in mind? Empowering a president to shakedown foreign leaders to help his domestic politics or funnel business to his private resorts? The Trump precedent will echo for years in arguments about executive power, and not in ways conservatives will like.
Lastly, most Republicans do not face a high cost within their own party for defending Trump. But, in a country becoming younger and more diverse, there’s little chance even these internal GOP politics remain static. The isolationists of the 1930s had the popular position at the time, but had considerable explaining to do for years after. So did the McCarthy backers of the 1950s. So did the civil rights opponents of the 1960s.