Are there hard limits on certain group memberships?

I can get some groups down to 0% like religious or motorist. But some groups seem to have hard caps like conservatives at 16.3%.

Is this intended? If so can there be a way to denote this such as innate bias for UK or something?

Also side question but does raising values above their shown limit(gdp, environment, etc…) have an effect? I can tell it takes that into account because if I barely pass the cap then do something negative it decreases, but if I pass it by a lot and do something negative it is still at max.

I think youth is unchanging but otherwise it’s just a matter of how extreme various policies allow you to be.
TBH it’s rather unrelaistic that you can get any of these groups down to 0%.
There’s even a policy to outright ban trade unionists, thereby bringing their membership to 0%. - I don’t think that’s how it ought to work. Trying to ban all trade unionists doesn’t mean nobody identifies as trade unionist anymore. There would be pushback. People who would want to organize trade unions while facing prosecution.

Similarly, it ought to be impossible to zero out religious membership.

Motorists might be nearly possible though. Nearly but not totally: It could always be an expensive hobby to have old timers or what ever. If a small niche of people keeps having gasoline guzzling cars, that will not have a huge impact on environment though.

Pretty much the only voting group you really ought to be able to get rid of (though it probably ought to be much harder than it currently is), is poverty. If you sufficiently boost poor people’s income, eventually they’ll move up to middle class. Universally.

EDIT: Maybe there should be a dark number mechanic. Realistically you wouldn’t actually precisely know every single person’s exact beliefs and priorities. So demographic analysis could be a mechanic, and if you outlaw something like trade unionists, that just pushes nearly 100% of trade unionists into the darkness without you necessarily noticing. (The remainder would presumably land in prisons or what ever?)

Like, this isn’t just about undecided voters who’ll decide at the voting booth, but rather about people actively hiding who they belong to from you.