First of all, there isn't any significant difference between any of those leftist outlets other than style. Centrist? Give me a break. The word "liberal" really doesn't work anymore...
lib·er·al
/ˈlib(ə)rəl/
adjective
1.
willing to respect or accept behavior or opinions different from one's own; open to new ideas.
2.
relating to or denoting a political and social philosophy that promotes individual rights, civil liberties, democracy, and free enterprise.
The left is angry because they are now being judged by the content of their character and not by the color of their skin.