We are in a time of where truth is hard to find. The D's might have good reasons to fight the results. And maybe they have good reasons for not fighting the results. Who knows? We are not in the back rooms.
There were sure a lot of commentary that Trump was not the legitimate president in the USA in 2016 because of the slight bias the EC gives to the R's these days.
Had the D's secured a resounding victory, all the allegations for possible fraud would not have mattered. In that, they clearly failed. And they failed because they have been failing their base since 1992.
I have a LinkedIn contact who was a poll worker in Maryland. From what she could see, the election was conducted properly--even though she was from the progressive left.
In my political days, I somehow had an hour-long discussion with an experienced Elections Canada official. He told me of some of the tricks political parties would use to win close elections. I believed most of those problems were solved when Canada (and the provinces) adopted rules about Voter ID before people get a ballot, circa 2000. Maybe today there are other issues.
I found it strange that the D's were against voter ID in the USA. (The D's would lose a few votes compared to the R's). But other commentators say voter ID is now mandatory in all states, and there is no opposition . I'm not in a position to know where the truth lies.
Anyways, all these allegations would go away in TDG elections.