part of today's ruling said that Arizona (or any other state) can check the federal registration form against other records (SSN, state tax records, etc) to verify citizenship if the registrant does not provide it.
"...while the NVRA forbids States to demand that an applicant submit additional information beyond that required by the Federal Form, it does not preclude States from 'deny[ing] registration based on information in their possession establishing the applicant’s ineligibility.'" Opinion page 12
Which is exactly the problem.
The onus to prove/disprove eligibility is on the state rather than the applicant. The State is barred from obtaining information from the applicant and instead must rely on information in their possession.
Meanwhile the foreigner is registered, and will vote.
A vote can not be undone.
Rather than control the front door, the borders/ports, everyone will be admitted to the country.
Then everyone within the country will be enabled to live here, unless encountered and then the state can try to determine if they are here illegally.
So with voting:
Rather than control who registers, everyone will be registered and admitted to the process.
Then everyone in the process will be enabled to vote unless the state can determine they are illegally registered.
Common sense: Control the point of entry - to the country or the process - rather than backstop it after the fact.