Which US professional sport athletes are the most socially liberal?

[James Monroe]

The sports establishment always seemed to be reactionary in comparison to other entertainment industries, especially when it comes to LGBT and women rights, so I wonder which league would contain the most athletes who rebelled against those values. By rebelling those values I mean being openly atheist, support same sex marriage, oppose the death penalty, and other liberal values. 

[James Monroe]

Yeah, NHL followed by the NBA.  Way down the list is the NFL and another big gap down to MLB.

  Now... I suspect baseball to be more socially liberal than the NFL. Its the league with probably has  the most misogynists playing, also the most militaristic out of the four leagues. Not trying to argue baseball is some liberal paradise though it does attract a somewhat more liberal fan base than the NFL.