Agreed. I wish people could just leave their personal politics at the door but that isn't going to happen anymore. Yes, I realize I am being hypocritical due to my prior comments.
It's quite simple. And this is again just my way of thinking and again, this may be easier said than done...
If you are hiring people for a project, you have to vet/gatekeep quite strictly. See what kind of personality/attitude they have, what they have on their bio, and how they behave on social media platforms.
You also have to have a rule to not allow politics to intersect with the job. Aside from what the game may contain (perhaps it has a slightly pro right wing message, but isn't anything super extreme, or even a slight left wing bent), you mustn't allow too much conversation about politics with the developer group. From the get go "You are allowed to have your opinions, but here we are trying to make a product to entertain others, politics are not allowed and if you decide to start an argument about it for whatever reason, you get a warning, and if you do it again, you will be booted out". Again, this isn't 100% how it should go maybe but it's the sort of mentality you need to have.
That's really the main issue, there needs to be someone who puts their foot down and goes "Enough is enough" and enforces the rules relatively strictly. And this may not work with community projects, but it should work when it's a proper project where the workers get paid (like an indie game project with a lead/producer/director paying workers to do the things they can't do by themselves) and have something to lose out on if they don't go along with the rules.
This isn't of course going into people who are unreliable and douchey, not for political reasons. I've dealt with people who even before I pay them for anything, show signs of being unreliable and lazy. I have spoken to someone who would act incredibly unclear when I ask them "How long do you generally take to do things?", as the one rule I have is "The person I am paying must be able to deliver on time depending on the complexity of the work and what's going on in their life", if they can't provide a proper answer, that's a red flag. Another weird red flag I've noticed, is if the person is incredibly eager to work on a project out of the blue and without enough actual substance to quantify the interest. This seems to be a sign the person is naive/nutty but I can't really 100% be certain of that. In short, be careful around incredibly eager types who sorta pounce on you despite not having a reason for it.
And to end this on a different note. You do need to ideally pay the people you work with. Free projects tend to rarely work out well from what I hear, so it's best to pay the people you hire as if it's a proper job for them, at least in the sense they are being paid to fulfill a certain requirement which may be long term or short term. And not only this, but both the employer and employee need to respect each other, or else shit breaks down.
I've said enough. And this is just my thoughts and experience so may not be 100% feasible in practice.