I would bet the election results would be even more in Trump's favor with a popular vote. The margins between liberals over conservatives are not as large in the big metro areas as the margins that go the other way in the rest of the country. The House of Representatives is a good indicator of that. Mostly conservative leaning republican.
Many republicans probably stay home in those populous blue states because they know which way it's going to go. The way that the politicians campaigned had mostly to do with the electoral college map, with it's battleground states etc.
With a popular vote map, the politicians would have campaigned differently and likely the demographic turnout would have been different.
I still believe the electoral college gives a more balanced representation of the entire country. Pretty ingenious, actually.