Fivethirtyeight points out that the chance of Trump winning the electoral college but not thee popular vote is now 10.7% (polls only forecast).
So the question has to be asked, is the result legitimate?
I would say that it would be legally and constitutionally legitimate, but morally and politically illegitimate.
Translation: Otherwise legal (ha!) decisions he makes are to be respected and obeyed, within the constitutional framework.
But they are entitled to no moral or political deference. He speaks for the government, but not for the people, either nationally and internationally. Every political or moral choice is subject to challenge within the constitutional framework, and following its rules.
Moreover, any attempt to change the legal or practical constitutional framework would be subject to particularly strict legal and political scrutiny. An example would be any attempt to change the rules allowing the filibuster of Supreme Court nominees, which not in the constitution, are protective of its balance.
Lets hope these questions do not get tested.