Minneapolis Voting rules - 1 person can vouch for 8
Voter Voucher - a person may vouch for another voter, signing an oath confirming personal knowledge of the address of the voter who is registering, subject to the following guidelines:
A voucher must be a pre-registered voter in the same precinct or a voter who registers in the same precinct on Election Day with one of the other authorized proofs of residence.
A person may vouch for a limit of eight voters.
A voter who is vouched for cannot vouch for another voter.
http://vote.minneapolismn.gov/voters/ELECTION-DAY-REGISTER