first of all, take this with some grain of salt because it comes from someone outside the US.

but I feel that, at least in public, the Republican presidents of the last decades, including W. have shown respect to the office, to the constitution, the structures of the nation and intelligence agencies (I can't imagine Bush publicly siding with a foreign government over the FBI).

while (I assume) Trump supporters will argue Donald isn't part of the "political establishment", it also simply means he lacks even the most basic respect for all of that.

(and interestingly, hardly anything of what I mentioned has anything to do with the actual politics)