A long and bitter presidential election comes to a close Tuesday when Americans choose between a second term for President Barack Obama and a new direction with former Massachusetts Gov. Mitt Romney.
CNN's reporters, correspondents, analysts and anchors share what they'll be watching for that might tip off how the election will go:
It's been called Obama's election "firewall." But truth be told, it's looking more and more like Romney's make-or-break state.
Consider the day's agenda. Late Monday, the Romney campaign revealed the GOP nominee and running mate Paul Ryan will make public appearances in Cleveland on Election Day in one last push for undecided voters. No other state can make the same claim.
What other state can boast an event in which the Romney campaign plane pulled into an aircraft hangar before thousands of cheering supporters? That bit of grandiose stage crafting was pulled off by the Romney campaign in Columbus on Monday night.
Despite the campaign's confidence in winning Ohio, a Republican source close to Romney's operation in the state said the result there will be "close, very close."
It might come down to Romney's opposition to the U.S. auto bailout. His "Let Detroit Go Bankrupt" op-ed in The New York Times in 2008 (a headline he did not write) may prove to be his downfall in Ohio, where one in eight jobs are tied to the auto industry. Who would have thought a newspaper column, not Romney's business career nor his record as governor of Massachusetts, would have the potential of denying him the White House?
Romney tried to mitigate the impact of the auto issue by making a discredited claim at an event in Ohio that Chrysler was considering moving all of its Jeep production to China. His campaign then continued to tell that story, in various renditions, in ads in the state to stinging reviews from the state's newspapers.
CNN senior congressional correspondent Dana Bash: Unexpected GOP struggles in Senate
The neck-and-neck presidential race might be dominating headlines, but there are a lot of rich dramas playing out across the country in the battle for control of the Senate.
Heading into Election Day, there are nearly a dozen true toss-up races that could go either way.
Republicans hold 47 seats. To retake control of the Senate, the GOP needs a net gain of four. With 23 Democratic seats up for grabs in a terrible economy, it seemed like a no-brainer that Republicans would be able to flip four. But it's now a struggle for the GOP.
The central reason is that they are defending several unexpected races on their own turf. Indiana's Senate race is now going to be one of the evening's early bellwethers to determine the balance of power in the Senate. GOP candidate Richard Mourdock's poll numbers plummeted in this red state after he awkwardly stated a few weeks ago that pregnancy from rape is a gift from God. Polls close at 7 p.m. ET, and if Democrat Joe Donnelly wins, it will set Republicans back -- especially since the GOP already expects to lose the seat vacated by retiring Sen. Olympia Snowe in Maine. The state's popular former governor, independent candidate Angus King, is on track to win there.
Here are three other nail-biters I'll be watching:
Virginia: With more than $80 million spent so far, it's the most expensive Senate race in the country. Former GOP Sen. George Allen is trying to get his seat back after a narrow defeat six years ago. The man who beat him, Jim Webb, is retiring and former governor and DNC chairman Tim Kaine hopes to keep the seat in Democratic hands.
Montana: Neither Republicans nor Democrats will even privately predict which way this will go. Incumbent Democrat Jon Tester is trying to hold on for a second term in this red state. GOP challenger Rep. Denny Rehberg started out the race about 1% ahead in the polls. Now, $50 million later, they're in the exact same place -- a 1% differential between them.
Massachusetts: Going into Election Day, Republican strategists were pessimistic about holding onto this red seat in the traditionally blue state. GOP Sen. Scott Brown had fallen behind his well-funded Democratic challenger, Elizabeth Warren -- a liberal icon who served as the president's former consumer advocate.
Brown's win in the race to fill the late Ted Kennedy's seat stunned the political world, and he insists he'll surprise everyone again. But the president is expected to take Massachusetts by double digits -- and with him at the top of the ticket, it may be hard for Brown to beat back a Warren win.
What to watch for on Election Night