A long and bitter presidential election comes to a close on Tuesday when Americans will 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 tell what they'll be watching for that might tip off how the election will go:
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 tossup 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, Republicans 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.
Borger: How will the white vs. nonwhite vote split
One important indicator I will be looking at Election Night is the question of ethnicity -- and how the white vs. the nonwhite population splits. In the 2008 election, 74% of the electorate was white. The percentage of white vote has declined recently because of the growth in the Hispanic and voting African-American population.
Given the ongoing Republican trouble with Hispanic voters and the assumption that African-Americans will, once again, vote overwhelmingly for the president, Mitt Romney needs a strong white turnout to help propel him to victory.
In an analysis by Republican pollster Bill McInturff, the question of the white/nonwhite divide is called the most "critical" of the election. His analysis shows that if the white percentage of the electorate drops to 72%, Obama will probably win the election.
One key to watch is how the white vote itself splits between Obama and Romney.
In the latest CNN/ORC International national poll taken from Friday to Sunday, Obama received 40% of the white vote while Romney got 57%. In 2008, Obama received 43% of the white vote, which means he is polling less than that currently.
Crowley: Virginia suburbs and I-4 corridor
The first thing I'll watch is the exit polls to see who's voting and where -- in particular, heavy Latino turnout in Colorado, Nevada, Virginia and Florida could indicate Obama wins those states.
Then, it's Virginia, Florida and Ohio.
I'll watch the Virginia suburbs of Washington, particularly the female vote. Romney won't win here, but he has to hold down Obama's numbers while running up his own score in the rural area. Romney has to win Virginia.
Florida is all about the Interstate 4 corridor. North of it votes Republican; south of it votes Democratic. The I-4 corridor decides.
Everyone will tell you to watch Lake, Stark and Hamilton counties in Ohio. There are good reasons to watch all of them, reasons no doubt delineated by my colleagues. But for me, it's all about Ottawa County, which has correctly