But it's important to remember the "left" raising flags about fraud in the 2016 election, and primary. Everything from harping on the legitimacy of a candidate that lost the popular vote, "not my president" protests, accusations of voting machine fraud, primary delegate issues, conflating gerrymandering with federal elections, etc...

In general, it seems whichever side loses is increasingly blaming "unfairness" to generate more outrage to de-legitimize winners of the election. ...rather than trying to appeal to more voters.

We're all losers in this situation because it is the voting system that keeps us from killing each other.

From the sounds of it, you think the beginning was 2020. There's a long history of implying the "other side's" win is questionable, across the globe and including the US.