I commonly argue positions I don't necessarily agree with.

Often these are ideas that I don't agree with, but I can't articulate exactly why I disagree.

When I argue it, I can get others to argue against the idea, and so I can discover points that I may not have been able to put to words.

It's essentially idea farming.

Plato called it dialectic

https://en.wikipedia.org/wiki/Dialectic

I wonder. I think some politicians argue deliberately and rationally to win over some followers. For them it does not matter what the truth is or whether they believe it themselves but how many people will be convinced to vote for them.

Their followers might not even believe it but still support and spread the argument, for their own selfish reasons.

Say Hitler pronouncing that Jews are an inferior race worthy of destroying. Did his followers really believe that when they agreed with him, or did it just seem in their self-interest to spread such propaganda further, and seize the property of Jews?

Just an example from past but I believe similar examples happen all the time. Some people argue in bad faith. If that is the case there is no reason to argue with them.

Objectively false. Proven by this comment alone.

Maybe you are emotionally invested in appearing, or believing yourself to be objective? Perhaps that's why posting a terse, pithy comment felt so satisfying. ;)

I don’t know how to interpret that. If you didn’t care you wouldn’t have responded.