The logic is anything but logical. Trump has stated that he would be a dictator in day one and has told voters that if they vote for him, they won’t need to vote ever again.
Technically, Trump said he might be a dictator for one day, and in context it was pretty obviously humorous. It has been repeated ad nauseum that Trump has declared outright that he would become a dictator from day one, and that characterization has been adopted as gospel truth.
Similarly, in context, Trump was telling a group of people who tend not to bother voting that it was important that they vote this time... and that he would get the country on track again, and that audience can go back to not voting in the future. He did not state nor imply that he would be president for life.
This is a big part of the problem - a politician says something that can be interpreted to mean something different, especially if taken out of context. That politician's opposition then take that out of context mischaracterization, and present it as if that's the only possible or reasonable interpretation. That mischaracterization gets repeated and amplified over and over again... until many people believe that the lie they've been told must be the truth, because they've heard it from so many people.
It happens to Harris too. Just look at the compilation of "what can be, unburdened by what has been" presented over and over and over. It's something she says a lot, and by itself it is completely devoid of any meaning whatsoever. But opponents to Harris present the many cases of her saying that phrase as if that's the entirety of her position... and they insinuate that it's a dog whistle for communism because it bears similarity to a phrase from Marx.