Whitey would've been tough to kill. Too dangerous, too smart, and way too connected. The Boston mob did try to recruit Flemmi and have him made. They wanted a mole inside their biggest partner/competitor but Flemmi wanted no part of it. Apparently he told the guys in Winter Hill about it afterwards and they all had a laugh.

I personally don't believe this about Leonetti and Bulger. Seems weird he would remember an inconsequential "Irish drug dealer and low life" like that so many years after the conversation. Besides Bulger wasn't paying tribute. He was paying debt owed by Winter Hill for a loan.