11:11 pm: NBC just called Ohio for Obama (the Post has not called the state yet). It looks as if Obama has been reelected. More thoughts soon.

10:55 pm: Romney gets his first important piece of battleground news as the Associated Press Post calls North Carolina for him (the Post has not called the state yet). It looks like Romney’s path to 270 is narrow indeed: He needs to sweep Florida, Virginia, Ohio and Colorado. All of them are too close to call. But Obama is leading in Ohio, and the Obama team professes confidence in Florida, both of which have Dem-leaning counties still to be counted.

10:37 pm: Howard Fineman, on MSNBC just now, reported that Romney’s high command is “sequestered” and has gone “radio silent” in response to reporter inquiries. Fineman speculated that Romney’s top advisers may be having a “tough conversation” about the current state of the map and what it says about Romney’s chances.

10:06 pm: NBC calls the Missouri Senate race for Claire McCaskill (the Post’s call is pending). Between this and Joe Donnelly winning in Indiana, the story continues to be that GOP primaries saddled the party with candidates who ended up costing the party seemingly certain wins in red states. The McCaskill win is also significant because outside groups poured huge sums into this race, too — McCaskill was a top target.

9:49 pm: Now we can cheer this one: Elizabeth Warren has won in Massachusetts, according to the Post’s projections. The Senate will get a true populist, a real fighter for the middle class, and a strong liberal voice (remember that viral video?). Keep an eye on Wisconsin; if Tammy Baldwin wins, it will further boost progressive ranks.

9:33 pm: The networks are calling the Ohio Senate race for Sherrod Brown. This was in one respect the most important Senate race in the country: The clearest referendum on whether outside money could tip a Senate race, regardless of the quality of the candidates. A lot of super PAC money just swirled down the drain.

9:29 pm: The first really big presidential news of the night: Networks are calling Wisconsin for Obama. That, plus Pennsylvania (which has also been called for Obama) dramatically reduces any chance Romney has of winning without Ohio. Meanwhile, all the southern states — which Romney was supposed to take off the board early — remain too close to call.

9:13 pm: Update: Whoops, I was wrong. The Massachusetts Senate race has not been called.

9:01 pm: The polls have closed in a whole batch of states, including Wisconsin and Michigan. NBC just called Michigan for Obama instantly. Remember all that talk about the state being in play?

8:50 pm: The big picture right now is that the early returns suggest that the state polling averages were pretty on point. The averages told us that Virginia, Florida and (to a lesser extent) North Carolina would be very close. They currently remain too close to call. Virginia may match or exceed 2008 turnout. The state polls may have gotten the 2012 electorate pretty close ti right.

8:32 pm: NBC just called the Connecticut Senate race for Dem Chris Murphy against GOPer Linda McMahon. That’s a big win for Dems. Remember, earlier in the cycle, McMahon’s massive spending put her ahead, and this was a state where Republicans had Democrats on the defensive.

No more Joe Lieberman. That means one less difficult “centrist” for Harry Reid to deal with; he’ll have an easier time getting unity with Murphy.

Also: Independent Angus King won in Maine; he’s expected to caucus with Dems.

8:26 pm: Unlike (apparently) Romney, Obama did prepare a concession speech.

8:11 pm: With 50 percent of the Florida vote in, it’s too close to call at Obama with 50 and Romney at 49. But that is early and absentee voting; the question is whether it will be enough to withstand Romney’s expected strong performance in election day voting.

7:50 pm: The Associated Press reports:

Virginia election officials said statewide turnout would likely meet or exceed the 2008 presidential election.

This could mean turnout could be replicating something like the 2008 electorate, after all. If so, that’s good news for Obama.

7:40 pm: How important are labor’s turnout efforts to Obama's chances in Ohio? Just in from the AFL-CIO:

The AFL-CIO political program in Ohio completed more than 800,000 voter contacts in the final four days of the 2012 election cycle, far exceeding previous election years. The unprecedented level of voter outreach is the capstone of the massive effort underway since Labor Day that has reached more than 2 million Ohio voters utilizing 80,000 volunteer shifts.

The polls have closed in Ohio, and early returns say it’s too close to call.

7:29 pm: Nevada journalist Jon Ralston Tweets:

Turnout in rural NV, where Romney will crush Obama, is only 13% of the electorate so far. Down from 2008 (15%). No rural surge detected.

And keep in mind that Obama leads among the massive early vote in Nevada, which means more pressure on Romney to do very well there tonight if he is going to have any chance of winning.

7:21 pm: The polls are closed in Virginia, but Dems report long lines remaining in Dem strongholds like Richmond, Hampton Roads, and Northern Virginia. Dems are working hard to urge voters to stay in line. Here the Obama ground operation could be key. One Dem closely monitoring the ground game emails: “Hearing that no one is leaving.”

7:00 pm: The polls just closed in Virginia. Here’s what to look for: How the vote is breaking in the swing counties of Manassas, Loudon, Henrico, Fairfax, and Virginia Beach. Watch Dem turnout — and the margin Obama is ahead — in Dem strongholds like Arlington, Alexandia, Richmond City, and Norfolk. Republicans need to win big in southwest Virginia and Chesterfield County.

6:55 p.m.: MSNBC is reporting that the Romney camp says he hasn’t written a concession speech — just a victory speech. Count me as extremely skeptical of that one, but if so, wow...

6:29: The Obama camp is feeling pretty good about turnout in Virginia. An Obama source emails:

This afternoon confirmed what we saw this morning. Turnout is high in the key precincts that we are tracking across the state. It is at or above the levels that we were anticipating.

Earlier today, Dems reported that they were pleased with the turnout their operation was producing on the major Virginia college campuses; there’s been some uncertainty about the youth vote, so that could be a good omen for the Obama camp.

6:14 p.m.: A good chart laying out what targets Dems need to hit in specific counties in Ohio and other battleground states is right here. Keep in mind that the results come in sporadically from different geographic regions within each state.

6:06 p.m.: Liveblogging the results right here. Early warning: Do not take the early exit polls seriously. Do not do it. In 2004, many Dems believed — based on the early exits — that John Kerry was running away with the race. You all may remember what followed.