Lot of illegals have stolen socials so I mean
This is true, but that doesn't mean they can vote. Their social security number needs to match their name, their driver's license, their place of residence, and their date of birth. Any mismatch and the registration fails.
What undocumented immigrants will do is use someone else's social (sometimes a random person's, more often than not, one loaned to them by a legal citizen they know) and use it to work for a company which requires a social. This is thorough enough to maintain employment but not thorough enough to vote.