You really think they are hapless to notice the lies? Trump has been on camera for decades. He was the butt of the joke for the Simpsons and countless shows. That was far before he got into politics!
The reality (that those people will never tell you about, instead pretending to be surprised) is that they knew he lied, but to others, and that he was going to shaft the others but not them. Why do you think people "fall" for scams like pyramid schemes? They know it is "too good to be true" but they think they are the ones that will scam others, they will get out of the scheme on top. Here they think others will get screwed more than they will; they thought Trump would ruin and destroy the woke, the women, the trans, the brown-skinned, the most recent immigrants, and they would have never cared a single second about it; but now he has driven up the price of gas and stuff, and they are suffering as much as everyone else; that is what is unacceptable, and a treason, for them.
You pretend people mean what they say and that they can be reasoned with; I say, and everyone who actually interacted with MAGA knows this, that the whole movement is based on bad faith and dog whistles and stuff that can't be said out loud. The lies, the pretense is there to toy with you, they are in on the joke and you are not.