I am absolutely against Trump and think he's done a lot of harm. But putting the onus of responsibility on the people who live in an insular community where everyone they know supports Trump, think right wing economic policies make sense due to their upbringing and culture, and are seriously led to believe that anyone can succeed with hard work, since they don't have access to the information about how bad the problem really is, they don't see the offensive and stupid things Trump does as they are stuck in a media and social media bubble that only reinforces their beliefs, and by the same token only sees Democrat politicians painted as incompetent idiots, it's unfair to say they're idiots, as even if they think to question it, everything around them encourages them to continue supporting him.
They're the product of human biases and their environment, same as we all are. They're mislead, but they're not stupid, and they're not necessarily idiots. They're just stuck in a propaganda bubble and social circle that reinforces their beliefs.
I know many people like to paint the opposition as idiots because it makes it easier to criticise in a way, when you ignore that they believe it for reasons that actually make sense to them and they may even have thought out. But understanding that they are real people that have actually given thought to their beliefs, even if they're incorrect, is actually going to be more helpful if you try to respectfully change their minds. If you understand their point of view, it will be much easier. Calling them idiots will only make them think you're more of an idiot, and you'll be much less likely to convince them of your views.
There are people all over the country who have broken out of those bubbles you're referring to. It's not that difficult. I did it and there's nothing special about me. All you need is the desire for truth. The internet makes it possible to find all the information you need and you can access it for free.
Ultimately you're advocating for empathy and that's commendable but it doesn't mean these people aren't idiots. Trumpers are actively avoiding introspection, curiosity, knowledge, and truth. If you asked me to define idiocy that's pretty much exactly what I would say. Is it helpful to call them that out loud? I don't really know. Probably not, but some things that are true are uncomfortable to acknowledge and the truth is that Trump's base is largely made up of idiots. Some by choice and others couldn't be anything else if they wanted to but I don't think that distinction matters all that much since the outcome is the same.