Some people might think the left has special venom just for Trump, but past Pubbie presidents received the same amount...even if they tried to snuggle up to Dems.
In the eyes of current libs/ progressives, all Republicans are evil scum who deserve whatever horrible things might happen to them. I remember even Eisenhower received similar opprobium from liberals, and he was a national hero. My parents, strong Democrats, liked Eisenhower. But the core of leftist Dems hated Eisenhower like they hated all Republicans.
I guarantee you if Mitt Romney were president, he'd be getting the same kind of veiled or overt death threats from insane progressives.