(Religious) pacifists are required to fund wars under this system already. No one would argue for higher protections for vegans than religion, which is already better protected constitutionally in the US. So unfortunately I think this is a non-starter for legal determination. Morally speaking, you could have that conversation, but it wouldn't slot in to our existing framework as it stands.

I think you might be able to argue academically that vegans have a right not to subsidize livestock industries there, but let's be honest for a second and see that this clause is entirely violated every goddamn day in the US for many many groups of marginalized people.

And I don't see that changing very soon either.

Values and principles are largely subjective. It's only through overwhelming, collective agreement that some things become so valuable as to be declared human rights, even when it's staunchly evident they are, e.g. the rights of LGBT people.

I think a lot more political debate similar to this has been voiced and argued about parentless adults being required to pay taxes to support schools. While I think one could easily argue that public schooling is a greater good all must contribute to in order to better society, (though I could easily find you people who would vehemently disagree for some cockamamie reason) there simply isn't that sort of collective thinking about veganism.

That said, I’m not sure if that concretely allows a vegan to derive a right to be vegan.

Jesum fuck, it's this kind of gatekeeping that keeps people from making better decisions because you make them think it has to be all or nothing.