In the Senate, with fewer seats in play, the math is simpler. If one or two of the most vulnerable Republicans -- in Virginia, Pennsylvania, Rhode Island, Tennessee and Missouri -- win decisively, the networks will know fairly early that the Democrats won't be able to reach their magic number of six needed to take control. But even if the Democrats sweep those races -- and hold New Jersey, which is in doubt -- the networks still won't be able to forecast a Democratic takeover until enough votes are counted in Montana, where polls close at 10 p.m. Eastern. The Democrats would have to unseat Montana's embattled GOP senator, Conrad Burns, to gain control.
The biggest behind-the-scenes change in network coverage involves what has been dubbed the Quarantine Room. Determined to avoid a rerun of recent years, when its exit polls leaked out by early afternoon to the Drudge Report, Slate and other Web sites, a media consortium is allowing two people from each of the networks and the Associated Press entree to a windowless room in New York. All cellphones, laptops and BlackBerrys will be confiscated. The designated staffers will pore over the exit polls but will not be allowed to communicate with their offices until 5 p.m.