I'm going to take Hitler off the table as it's been four score minus 29 days since Hitler died. We're almost as far along since Hitler's death as President Lincoln was from the founding of the nation when he gave the Gettysburg address. Unless you think the South is still harboring a grudge against the North, I'm going to assume that Europeans have laid Hitler to rest after four generations. Maybe the modern Soviet Union before it fell is closer to the model for Europeans now?
I'll accept your list of variables, but I'm going to assume that the right is as far from center as the left is. I'm going to discount "far right" and "far right" as those are partisan views of the other side.
That said...
It could be leftists aren’t interested in pressing on after legal issues.
Seriously... when have you EVER seen that happen?!? The left doubles down every time they get defeated on an issue. Have you ever seen them pick up their ball and go home?
In my opinion, if the left thinks they are going to be beaten by a right-wing candidate, that's their justification for nullifying primaries, kicking them off the ballot, and jailing them. If they are surprised and actually lose an election, they assassinate the winner (Polonium-210 anyone?). The next time the left regains control, they crack down on future elections (see Chavez and Maduro in Venezuela, Daniel Ortega in Nicaragua). How many people have fallen out of high-rise windows in Moscow lately? It's just how they roll.
-PJ
Robert Fico in Slovakia and President Trump here in the United States.