What if they register their ideology as a religion? Iirc it is a protected class in US so they cannot be banned due to it.
However people getting banned like this rarely are inventive enough to figure out ways to fight back.
The thing about the law is that it doesn't operate like code. You can't just cast<Religion>(ideology) and expect it to work within the framework of law, because the law is (luckily) interpreted by people who expect it to be taken advantage of by the unscrupulous.
Otherwise, literally every corporation would already have registered themselves as a religion just to avoid paying taxes.
Maybe a case could be made for political affiliation under "creed," since there appears to be no specific legal definition for that[1], although the consensus seems to be centered around religious belief.
In any case, since one can (and many people do) change their political affiliations often, I would expect such a law to meet with some extreme legal challenges at the very least, because it seems like such an obvious attempt to game the system, particularly since "discrimination against a political group" is pretty much the purpose of other political groups.
[0]https://en.wikipedia.org/wiki/Protected_group
[1]https://law.stackexchange.com/questions/8686/what-is-a-creed...
I personally think there's something fundamentally undemocratic about barring discrimination against political ideology because that comes too close to interfering with freedom of speech or freedom of association or the exercise of politics itself.
Those laws don't exist because we don't agree with their reasons. They exist to protect people who have been categorically repressed for hundreds of years.