Looks like you replied while I edited the post. I should have edited a bit more before posting the reply, sorry. The edit probably addresses what you wrote.
I also learned that if you are too dismissive, then they will often continue to hunt you down.
Don't be dismissive. Be indifferent. There is a huge difference. Dismissive can be interpreted as "I know better than you, neener neener neener!" Indifference can be interpreted many different ways at first, but if they persist then showing indifference is like arguing with a rock. No amount of shouting at the rock will elicit a meaningful response.
I will use a variation of the above, and flee. This subject, however, is not something I'm going to run away from because my patience with people who deploy such tactics is growing thin. So I'd rather stomp it into the ground, and prevent them from getting back up.
You don't need to convince them, and they don't need to convince you. Nobody needs convincing. There is no point to the discussion. It serves no purpose. Remember that.
There is no need to flee because the discussion is pointless. Fleeing would be a statement. There is no need to stomp them into the ground, that is also a statement. If there is no purpose to the discussion, you can politely ask them to end it. If they still continue, just remove yourself from the situation; perhaps "I'll go talk a walk to give you some time to calm down", or "thanks for spending time with me, but I I'm starting to think of other things I'd rather do right now". Again, these are not statements about your viewpoints, they are statements that your socialization is voluntary and you find their persistence to talk about a fruitless topic to be a waste of your valuable time.