Firstly, Democratic establishment goes out of their way to not say these. Which is their mistake, GOP has no equivalent problem to accuse democrats of evil.
Second, he literally said he aspires to be a dictator, talks approvingly about dictators, and he does engage in literal extremist rhetoric on his rallies. You can be Nazi, an extremist, a dictator while not being literally Hitler in every single detail.
He likes when people say that about him. Not saying those is just lying, insisting that others dont say those is insisting on everyone lying.