> The Republicans in particular are not going to change the current system, and Trump, even if he wanted to, can't do it without a 2/3rds majority for the constitutional change.
There are actually two ways to pass a constitutional amendment. 2/3 of both Federal legislative houses is one, but they can also do it with 2/3 of all state legislatures.
Republicans do very well in the state legislatures, they're only about five states short of the latter threshold.
2018 is likely to be a bad year for Democrats, there's a huge number of seats to defend and only a handful of Republican seats that must be defended, with only like 2-3 competitive seats. A very real possibility is that this turns into the usual midterm bloodbath and they pick up a few more seats/legislatures and start pushing constitutional amendments on wedge/social issues to lock in their wins.
People's adherence to this as a "religious document" is oversold - the document includes a method to change itself, and this is "playing by the rules". But frankly they wouldn't even think twice before rationalizing, when presented with the opportunity to lock in their wins for multiple decades.
You're right about it being in their best interest not to mess with the election system right now. The multi-level (state/federal) and district-by-district/state-by-state nature of the system favors them heavily compared to the popular vote. Republicans have near total dominance of all levels of government, with what amounts to a popular loss. One thing they may change is to have more blue states start splitting their electoral votes, like Nebraska and Maine do. States get to determine how their electoral votes are allocated, and Republicans control many of the "blue" states' governments (eg Michigan, Wisconsin, etc). Republicans can essentially make those states not count for Democrats electorally, since they will go half-and-half for both Republicans and Democrats (+/- a few seats).