Here are the closing times in the Presidential swing states (with Pennsylvania added, due to Mitt's late push there) and in the states with close Senate races:
Presidential swing states:
7:30pm: Ohio, North Carolina
8pm: Florida*, Pennsylvania, New Hampshire
9pm: Wisconsin, Colorado
10pm: Iowa, Nevada
*FL polls close at 7pm local time. But a few counties are in the Central time zone.
States with close Senate races:
7pm: Virginia, Indiana
8pm: Massachusetts, Connecticut, Missouri
9pm: Wisconsin, Arizona, Nebraska
10pm: Montana, Nevada
11pm: North Dakota
The break-even point in the Senate tonight is almost geographical: barring upsets in Western states where we're overwhelmingly favored (NM, HI), we are guaranteed to break even in the Senate if we win in all the seriously contested races in states east of and bordering on the Mississippi. If we win all of those, then every state in the list above that we win in the Plains and further west adds to our current margin. Losing states along and east of the Mississippi needs to be balanced out by gains further west in order to remain even.
So unlike the Presidential race which, if we're lucky, will be over by 8pm or so, the earliest we might know that we're coming out ahead in the Senate (if we are) would be if we pick up the Arizona seat, which is a longshot. We've got better shots at the 10pm pair.
But if it's gonna be a sucky night for the Senate, we'll find out pretty early. Hopefully that won't be the case.
My big hope for the evening is that Romney's ultimate share of the popular vote settles out at somewhere in the 47% range. I would so love for him to have to carry that number around with him for the rest of his days.
Some early liveblogging, while Sir Charles does his warmup exercises:
With 9% of the vote in in Indiana, Donnelly's pulled ahead of Mourdock by ~9000 votes. Good news.
With 1% of the vote in, Allen's 10,000 votes ahead of Kaine in Virginia. Means nothing without knowing which part of the state, of course.
9:40pm - NBC has called Pennsylvania and Wisconsin for Obama.
9:43pm - NBC calls Massachusetts for Elizabeth Warren, and Indiana for Joe Donnelly.