Would having numerous social security numbers aid someone in making campaign contributions to self or other?
Could someone deposit funds in banks using the designee social security numbers under which the accounts would be available, then someone else later withdraw these funds using that designated social security number?
Are social security numbers a data point for passport apps? For wire transfers of funds?
Basically the answer to all of those is yes. It’s harder to get away with today, but it was rather easy for the most all of the 20th century as long as you were using a number you knew wasn’t being used by anyone else (ie, a dead person’s number). Using such numbers and other identity documents with different or slightly different names enable multiple identities for all such shenanigans.