If I read this correctly, Kaufman's not dead because the SSA doesn't say he's dead. I, for one, would not be surprised to discover that the SSA has that kind of authority.
Indeed, Kaufman had enough dealings and funnelings of money that I find it hard to believe they would not have noted his death.
Who knows, maybe he's been dutifully paying his taxes all these many years.
Don't bother checking his voter registration. Dead democrats remain on the rolls all the time.