Earlier this year, Democrats caved in to their left wing by canceling a debate hosted by FNC on the grounds that Fox wouldn't provide a fair forum for their presidential aspirants. Never mind that in 2003, the Dems eagerly and without complaint participated in a FNC-sponsored debate, the last CNN-sponsored debate had the network pulling far more strings than it should have, skewing the process in a way that it wanted.
As noted by Howard Mortman, the liberal dominated network deliberately placed the three highest-polling candidates right next to each other, thereby minimizing the exposure the "lesser" candidates received. Moderator Wolf Blitzer also took more time for himself than every candidate except Barack Obama and Hillary Clinton.