if the election was conducted based on the popular votes, then the Republican voters in deep blue states such as California and Maryland would have come out to vote rather than sitting at home.
It is just your opinion. No one knows how it would be.
Not how the system is setup in america. For better or worse. And the democrats had many opportunities to attack the electoral college if they wanted and call for reforms. Lost twice because of it this century alone so they should. But they did nothing about it.
I said about legality, not that Trump is defacto president (you cannot do anything with it).
Honestly, Electoral College, as well as Congress, Senate, Supreme Court and other U.S. federal government institutions are absolutely illegal. America had to follow all legal procedures to secede from the United Kingdom, which it hadn't (just self-proclaimed), so U.S. govt no more legal than L/DNR in the Ukraine. Only because US have powerful military forces other countries acknowledge US govt as legal and count L/DNR "illegal separatists".