In other words, my takeaway has been that if you aren’t going to do at least some of your own research, you shouldn’t be voting (let alone running for office), and you definitely shouldn’t be making arguments. (Corollary: you shouldn’t even be boosting other people’s arguments, no matter how much you may personally like them.)

Bringing this back around to the topic of your post: The people in your second category don’t usually do their own research, but they do, necessarily, think that talking to their peers and evaluating their reasoning is valuable.

The problem tends to be that they don’t know how bad they are at evaluating anyone’s reasoning.

So, wondering which topics you have faulty information on is a good start when it comes to not being those people.

They hold their ignorance to be as valuable as your intelligence.

We have quite a few people like this IRL…
Actually, a good number of people we disagree with – at least, I would disagree with – have faulty information on one topic or another. Out of frustration, I may resent them for not listening to arguments from my side, but at least the issue could be framed as “they hold their intelligence as valuable/more valuable than our intelligence”.
Makes me wonder which topics I have faulty information on.

OTOH, there are people who like to go around claiming how their opponents are “over-educated”, and more generally are going out of their way to stay ignorant. To put the quoted sentence another way, these people value their opinion as more valuable than your facts.
Those… yikes.

Avoid them. Use spears if necessary.