Don't engage... These people are bitter about their lives. Just walk away. Let success speak for itself.

I think it is more Rural versus Urban divide.
For fun lets take a look at gun control. If you live out in the middle of nowhere, you have a gun. Possibly a whole locker full of them. Any call to the police, animal control, etc, will require an hour. During which time something has already mauled you, and is working its way through the rest of your family.
If you live in a city you are surrounded by people. They are everywhere. If you wake up in the middle of the night and someone broke into your home, it's understandable you would want to shoot them. But there is good odds your going to miss. And with a bit of shit luck, you just shot someone who was asleep two apartments over.
Don't get me wrong, the radical far ends are batshit and probably need meds. But people are usually the way they are due to their circumstances.

Ben Shapiro has a video on this subject. "Ben Shapiro - 10 Rules For Fighting The Left"

You have to transcend yourself into the person you are debating so that you can either agree with them to find common ground and/or know the points they are going to make. You need to relate to them in some sense if you are going to continue the debate at all because they need to know that the person they are arguing with are like-minded. However even if you are debating you should always have something in your mind to realise that you may be wrong. As Nietzsche simply puts it: "Evil is the force that believes its knowledge it correct" - so be as viable and evident as possible, if that does not work try to find some similar ground to work with - they will be more likely to see your point of view.

There is a difference between winning an argument/dispute/debate compared to showing them your opinion - like they are going inside your head. If they do see your opinion and where you are coming from and still refute it, there is nothing to be done as far as I am concerned, you cannot make everyone like you, just move to the next person, best option we got.

I would say you have to try to mold the feelings with the facts. An example I would give, would be if someone supports raising the age to own a firearm to 21, how can they explain that to a single mother trying to defend her self in the inner-city when she has a child?

The radicals will stay that way until they give it up on their own. The responsibility is to find the ones that are open to reason, in an effort to grow the middle into the majority. Not easy, or quick, but it's the only hope for true progress

Why It's Useful to Talk to People You Don't Agree With | Jordan B Peterson

Maybe, start by asking them this question: IF you were wrong, would you want someone to tell you? Their answer will tell you if you should continue.