When will we know a winner on election night?

One piece of advice for anyone planning to tune in to election night coverage Tuesday: "Have a couple of cups of coffee," CBS News director of elections Anthony Salvanto said. It's going to be a long night.

Though polls in some states, like the key battleground of Virginia, will close at 7 p.m. EDT, others, including the critical swing state of Iowa, won't close until 10 p.m. EDT - "and most of the battlegrounds may even still be counting votes at that point," Salvanto said.

"I don't think we'll know the winner there for a while, especially if it ends up as close as it looks right now - that could be hours," he said, predicting only a one- or two-point gap between President Obama and Mitt Romney across battleground states. But as returns come in throughout the night, Salvanto added, results from "battlegrounds within the battlegrounds" - crucial voting blocs in swing states - could sketch a rough outline of how the election will likely turn out.

• Battlegrounds: The way to win
• Complete coverage: Campaign 2012

Citing Hispanics, African-Americans, women, seniors in Florida, and suburban white men, Salvanto said watching the way those groups are breaking "will give us indications of maybe which way this is leaning. It'll generate some excitement."

In 2008, for example, typically conservative small towns and rural areas defected, making up a critical part of then-candidate Obama's coalition. Recent polling, Salvanto said, suggests those areas may shift back to Romney on Tuesday, meaning the president "would have to make up that difference somewhere else," like around cities or among women.

Above all else, though, the number one thing to watch for Tuesday night: "Turnout," Salvanto said.

"When you see an election that is this close, with each partisan side in their respective camps and so few undecided voters, it becomes about which candidate gets their folks out to the polls," he continued. "And people often say, 'Oh it's all about turnout.' But in this one, it really is."

[abbe91]

When will we know a winner on election night?

Now we do ...

[smigit19]

In these last four years I have learn an abundance of information about the President of the U.S. some good some bad but it all comes down to what has he done and accomplished that he had said he was going to do in the last campaign. Yes he did change the U.S. and by doing so he put us so far into debt we don't have a rock to sit on. Yes he pulled the troops out but only recently hell we still have troops overseas right now. Did he not tell us we would pull out COMPLETELY did he also not tell us he was going to create more jobs not fire millions and only create a thousand jobs but he said create millions of jobs where are they I ask? Dare I say spread the wealth because the people who do have jobs get hard earned money taken away for someone who is to lazy to even tie their own damn shoe. I have worked my butt off these last four years for what? Nothing he has given us nothing but he has taken and that's all he has done and now look where we are at.

[smigit19]

In these last four years I have learn an abundance of information about the President of the U.S. some good some bad but it all comes down to what has he done and accomplished that he had said he was going to do in the last campaign. Yes he did change the U.S. and by doing so he put us so far into debt we don't have a rock to sit on. Yes he pulled the troops out but only recently hell we still have troops overseas right now. Did he not tell us we would pull out COMPLETELY did he also not tell us he was going to create more jobs not fire millions and only create a thousand jobs but he said create millions of jobs where are they I ask? Dare I say spread the wealth because the people who do have jobs get hard earned money taken away for someone who is to lazy to even tie their own damn shoe. I have worked my butt off these last four years for what? Nothing he has given us nothing but he has taken and that's all he has done and now look where we are at.

[GOP-R--Con-Men]

Thank goodness the country rejected you're on your own for we're all in this together which we truly are.

[khf1956]

I feel sorry for you. As your northern neighbour I see so much ignorance and for those of you who do not know the definition of ignorance, it is being uninformed. You allow yourself to be misled by smoke and mirrors. I watch with horror the numbers of Americans who allow propoganda to sway their decision as opposed to critical thought.
It scares me to have a neighbour who actually does have weapons of mass destructions lead by someone so closely related to industry, which in your country seems to be armaments.
I care about you. I have travelled through many states and met many wonderful people. You deserve better than Romney.

[rasrfasu]

GO ROMNEY!!! Rooting for you in NY!!!! It's time for change Mr. Barack Obama!!! Move over for our fave: President Mitt Romney. Thank you.

[Filmguy870]

Nate Silver ROCKS!!!!!

[vimitake]

Romney lost. lol.

[aubfmet]

Iowa, won't close until 10 p.m. EDT ___but EDT ended last week. Now it's EST.

[brasileira2]

To: WHAT-T-F
I would be ashamed to call myself an American without having a clue on how to spell. Go back to school Dude! Your argument is so childlike...

To: Flustered in Florida
You sound like an intelligent American citizen. Well said

[DJPEsq]

The winner of the presidential race .. will be served with our Thanksgiving Turkey ...

... not sure which will be which

[Flustered_in_Florida]

Dear What_T_F,
As a concerned, voting American I also have questions. Why is it always the racist redneck whose hate-laidened comments are so full of errors they are barely legible. As a woman who grew up in the deep south I understand the nature of ignorance is to beget ignorance but, why does your ignorence prevent you from dropping this nonsense even after his office produced a LEGAL copy of his birth certificate. If you truly have read some of President Obama's literary works, I challenge you to take a second to compare his writings to some of your own. Reflect on some of the basic spelling, grammar, and use of the English language and understand that this is a man running on a platform of freedom of education for all, no matter their economic standing! This means YOU! You too can have a seat at the adult table, having intelligent conversations about the direction of our country, and make informed and educated decisions, without having to resort to all measure of slander or reference to Donald Trump to sway the hearts and minds of others.....I know it is in your nature to look for the proverbial "ninja" in the wood pile, but don't vote against your own interests because he doesn't look enough like you......that's just silly!

[seabass6251]

When Americans consider their "own interests" over the good of the country is exactly the point in time we become a socialist nation.

What was it that Kennedy stated in his inaugural address about this exact same thing?

[AlenaJoy]

Well, according to more than one source, both considered reliable, the birth certificate was doctored. So we're supposed to believe it's real? Why did Pres Obama seal his college records and visa? A President should be transparent. He had something to hide. Mr Trump may not be well liked by many but I think overall he's a man of integrity. He hates lying. I can't blame him for wanting to know the truth.