He was apparently popular. I think they’re bizarrely hoping the dead man’s name will get voters out to the polls to help their candidates who might hvae contested primaries, then they can fill the seat with whomever they want.
My take was a bit different. It sounds like Jeffries was having trouble getting enough petition signatures to qualify for the primary. So while they were collecting petition signatures for the dead guy, they were also getting petition signatures for Jeffries.