He says things like "I wish I had general's like Hitler's" or his political opponents are the "enemy within" and he would harness the military against them if he gets in power, and that migrants are criminals.
I really don't know how you can equate something as uncontroversial as "1+1=2" with such controversial and divisive statements.
It is a neutral statement that Trump is objectively terrible. By contrast it is propaganda to defend him when he claims 2+2=5, which he does on a regularly basis.
And this doesn't have anything to do with "the left" a ton of conservative Republicans have admitted that Trump is objectively terrible.