Many of those who complain about "political correctness" just want to say racist/sexist/bigoted things without having to deal with the fact that such is no longer socially acceptable. This isn't true of every opponent of political correctness, but it's true of enough people to be noticeable.
Cenk Uygur just said that if Bernie wins MA, CO & MN on ST, "I think he's the favorite". Seriously.
It'll be impossible for Sanders to match Clinton's delegate count on Super Tuesday, but Cenk would be right in saying that winning those states would keep him on the map. To be a viable contender for the nomination, he'd have to win Ohio and/or Illinois on the 15th. If he can't, it's over.