As some already said, after 1932 the boss of bosses position in the US Mafia was nixed and there was only chairman of the board with no special power over the other bosses. Yes, there were always some bosses which were more powerful then the rest of the representatives, like Giancana during one period or Gambino during another period, by having influence over other bosses regarding commission votes and stuff. For example during one period Lucchese, Gambino, the Genovese rep and Giancana usually voted the same way and completely controlled the whole commission. There were also meetings regarding some conflict and sometimes Giancana had the last word, again depending on the time period, the type of situation and which boss possessed more power at the time. There are also examples when everyone waited for Tommy Brown's vote or opinion etc. And yes, they all had their own independent votes but still not everyone was equal in terms of power on the round table.