This is not comparable. A couple groups on the far left is not the same as the leader of the party. I don’t see any major figure on the left: Bernie, Obama, AOC, Biden, Hillary, Pelosi etc claiming fraud.
> Hillary Clinton dismissed President Trump as an “illegitimate president” and suggested that “he knows” that he stole the 2016 presidential election in a CBS News interview to be aired Sunday.
It's very much on record that the Trump campaign reached out to the Ukraine to see if they'd dig up dirt on Hunter Biden and the Biden campaign in general, and that's what Clinton is referring to.
Unless of course you think incumbent leaders should be able to use foreign intelligence services as a part of their campaign strategy to attack their oppoosition?
From https://www.washingtonpost.com/politics/hillary-clinton-trum..., among literally hundreds of other instances claiming the election was stolen, rigged, Russianed, whatever.