I've built a DAO tool that requires passport verification and allows voting on binding proposals with quadratic voting. Each proposal defines a series of transactions to execute on chain.
As far as a state level attack, it's possible. A complete solution to Sybil resistance is not simple.
The passport verification service is at https://coinpassport.net if you would like more information.
Stripe Identity seems to very explicitly not be intended to guarantee any form of uniqueness.