By that I mean which mobster lead to the mobs downfall. The mob is still here and still making tons of money obviously but not like they did years ago before Giuliani came in and cleaned everything up in NYC. A lot of people are also getting locked up. So if there is one person who do you think it is? I think it was john gotti. He put the mob too out in the open, and served as the poster boy for what people and kids thought a mobster should look like and how a mobster should conduct himself. Which was the wrong way. Every old school wiseguy knows he wasnt doing what cosa nostra rules said. He was flaunting his money and lifestyle too much. He should've kept his business to himself. And I don't even blame sammy for flipping on him. John double crossed him and he deserved it. That's my opinion. But I'm sure gotti isn't the only one. There had to be many others who contributed to the mobs downfall. The justice department deserves a lot of credit also. But that's a different story.