I'm not American, but do know a bit about the US political system.
First of all I wanted to comment on the fact Trump lost the so called popular vote. While this might be true, it doesn't really say much. Trump based his campaign on the current election system, and did little to none campaign in some districts. For example in the District of Columbia, Clinton won with 90.48% of the votes, which alone gave her 260.000 votes over Trump. So the popular vote doesn't say too much.
As for the electoral system, we must ask ourself why it was put into place in the first place? Simple answer is, to take a bit of power away by the people. The founding father feared people could be manipulated into electing a tyrant into place, and thus they created a safety buffer for this in the form of the electoral college system.
I do think this should be kept into place, people should be protected against themself. In these days, where media biased and fake news are an ongoing issue, it's hard for a lot of people make a rational decision. Tons of people see Trump as someone bad, but how many people can actually give valid arguments as of exactly why? Did he have some childish tweets? Sure he did, can't deny that, but does it make him a bad president? Those tweets for example opened up the door for negotiations with North Korea. Did he say against someone he would like to grab a womens pussy? Sure, but what guy never made such a remark when in private? The GDP under Trump is sky high. No wars have been broken out so far, he gives his wage to charity, and a lot of other things. Yet, most of this does not reach the news, instead, we had to read for 2 years how he will be impeached and how Russia did all sorts of things wrong, without even the slightest piece of evidence. Because that's key, evidence. Noone is guilty of anything, unless proven guilt behing reasonable doubt.
What the democrats should be doing now, is focussing on themself. Ask themself why they lost the elections, instead of trying to find a scapegoat. And most of all, find unity within their own party, as well as with the others. Sabotaging others will help noone in the end.