Las Vegas, Nevada (CNN) – With both campaigns and political parties mounting efforts to get out as many voters as possible on Tuesday, Democratic incumbent Sen. Harry Reid of Nevada and Republican challenger Sharron Angle are preparing for what could be a very late night to decide who is the victor in the high-stakes battle for the Senate seat.
The contest is one of the most closely watched Senate races in the nation and could decide which party controls it.
With polls showing the contest a virtual dead heat, both sides say the outcome could be decided by a very narrow margin.
The campaigns, party groups and outside organizations have battled over the airwaves, running a seemingly continuous series of ads attacking the other candidate. Some estimates put the amount spent on the race at $50 million.
On the day before the election, Reid and Angle chose markedly different approaches.
But the message from both was essentially the same: The race is close, don't take anything for granted and go to the polls.
Reid, fighting for his political survival, brought in first lady Michelle Obama for a high-energy, high-profile, get-out-the-vote rally Monday.
"We are heading into that final round - it is right before us," Reid, a former boxer, told the crowd. "Let's take no chances."
"I am not finished fighting," he told the crowd, adding that he has battled his entire life. "I am not finished fighting for jobs ... or keeping Nevadans in their homes or to protect Social Security."
The longtime senator is facing an uphill climb partly because of the state's dire economic picture - it has the nation's highest unemployment rate at 14.4 percent, as well as the highest foreclosure rate.
Reid pointed out some of his accomplishments as Senate majority leader, saying he would do more to help create jobs.
The first lady called him a strong leader.
"Because of leaders like Harry, so much has been accomplished in such a short period of time," Michelle Obama said, while transitioning into a strong defense of her husband's record.
"Barack knows too many folks are out of work right now," she said, noting that his administration has cut taxes for middle-class families and small businesses - more than most people realize, she added.
Acknowledging the frustration across the country, Obama urged audience members to show their support for the administration.
"This election is not just about what we have accomplished, but what we have left to do," Obama said. She also asked for patience, saying her husband's election was not a single event but "was about building a movement for change."
Angle chose a more low-key approach, dropping by a senior center for lunch and a Reno restaurant to chat with voters, according to the campaign. Reporters were not invited to see her at either stop.
She also did a series of television and radio interviews, including talks with conservative talk show hosts Dennis Miller, Hugh Hewitt, Lars Larson and Mark Levin. Angle participated as well in a tele-town hall meeting with Sen. John McCain, who campaigned with her at a rally Friday in Nevada.
"I'm very cautiously optimistic," she told Fox News Monday night. "It's one of those things that we don't try to even forecast until we get all of the results in. So we are eager to have everyone get out and vote."
Angle went after Reid over the state's economy, saying he hasn't done enough to help repair it.
"Certainly we do hold him responsible here in Nevada. When he went in as senate majority leader, we were at 4.4 percent unemployment and now ... we are at 14.4 percent unemployment," she said in a television interview. "But when you put in the underemployed and those who have quit looking for jobs, we are really a 22.3 percent unemployment. And we lay those (figures) squarely at Harry Reid's doorstep."
Reid attacked Angle as an extremist, much as his campaign has done since she won a June primary in an upset victory largely due to support from Tea Party activists.