Did Fox get sucked into Fringe’s parallel universe and trade places with NBC? The network is down 29 percent in the demo this fall, more than any other major broadcaster. Blame a softer World Series and shows like The Mob Doctor (not to mention the departure of House). Also not helping: The X Factor ratings have slipped to 10.3 million for Wednesday performance shows despite a season 2 overhaul with new judges (Britney Spears and Demi Lovato) and format tweaks. Throwing in red-carpet refugees Khloé Kardashian and Mario Lopez as co-hosts for the live episodes didn’t improve things either. Fox typically comes from behind to win the TV season, starting in January (when American Idol returns), and it has Kevin Williamson’s promising thriller, The Following, in the wings. But this year the network will have a steeper hill to climb.