Why are athletes, sports announcers and team owners held to a higher standards than politicians?

Rep Steve King appeared on MSNBC in a panel with Chris Hayes and others.  During the telecast, it was observed that the Republican Convention attendees were predominately white and it didn't  represent an example of diversity.

But then Steve King really put his foot in his mouth saying  "I'd ask you to go back through history and figure out, where are these contributions that have been made by these other categories of people that you're talking about, where did any other subgroup of people contribute more to civilization?"

What shocked me is that that not one of the other panelists took Steve King to the wood shed.  Where were Chris Hayes and the other panelists?  I understand that MSNBC is trying to become a more balanced network, but by letting Steve King make these comments without blasting him, the network is not being more balanced, but being Fox News. 

If ‪SteveKing was an athlete, a sports commentator, a coach or an owner and said such a racist thing, he would be banished from the league or fired.‪ MargeSchott, ‪DonaldSterling ‪Jimmythegreek were either forced to sell or fired after making racist statements. But because SteveKing a politician, he isn't held to such a high standard.