It seems like most of the polling organizations that did the worst during this election did poorly because they were way off-base with their likely voter model. No one in the press seemed to notice the scale of the turn-out machine Obama constructed since 2010. Many organizations (including, apparently, Romney's internal pollsters) assumed a turnout somewhere between '08 and '10 levels, when the Democrats managed to match or beat 2008 turnout in critical areas.

I'm not sure it's really a question of ideological bias so much as filtering the raw data through a backward-looking model.