LAS VEGAS — If the nation's most closely watched Senate race is a battle, the campaign offices and neighborhoods of recession-ravaged Nevada were the trenches on Monday in the final hours before Election Day.

Volunteers at GOP offices made their best cold-call pitches: Help Sharron Angle beat U.S. Sen. Harry Reid. Democrats — one dressed as a chicken to mock Angle's refusal to take questions from the media — hurried from door to door, urging voters in a state hit hard by unemployment and the housing bust to give the Senate majority leader another chance.

Last-minute and, at times, desperate get-out-the-vote drives picked up speed in the state and across the country, with some key races, like Reid-Angle, so close that they could be decided by just a couple votes per precinct.

Among the tightest races were in Colorado, Pennsylvania, West Virginia, Florida and Illinois, with the outcomes helping determine how close Republicans will get to taking control of the Senate and if they will gain the majority of governorships.

"I need you in the next few hours," Reid said, alongside first lady Michelle Obama at a suburban Las Vegas rally. "Don't hope someone else will work harder than you. You need to knock on that extra door. You need to make that extra phone call."

Reid's words were at times drowned out by the roaring crowd, who chanted his name and waved campaign signs.

The tea party-backed candidate, Angle, urged her supporters to turn out.

"They understand full well that I am on the verge of ending Harry Reid's campaign," Angle said in an e-mail.

The intense pace of the final day of campaigning — with television and radio advertisements saturating the airwaves, robocalls ringing tens of thousands of phones and countless knocks on doors — annoyed some voters.

A TV advertising shootout has been under way for months — Angle's ads blame Reid for Nevada's devastated economy, while Reid has sought to paint Angle as a conservative extremist who would gut Social Security and turn her back on the middle class.

At a strip mall in Las Vegas, a Republican office looked like a pre-election assembly line as college students from Brigham Young University furiously dialed up voters. The walls were plastered with Sharron Angle political signs.

One photo was of Reid, with the caption: "Replace this face."

Volunteers called up Nevadans and asked if they had voted yet. If they hadn't, the GOP planned to dispatch volunteers to their doors to make an in-person plea to vote for Angle.

"The reason why I'm here is to protect my future," said volunteer Carl Kimmerley, a 23-year-old BYU junior economics major who wore a T-shirt that said "Remember November, Vote Republican."

Democrats, meanwhile, targeted hundreds of neighborhoods rich in registered Democrats, from Las Vegas to Reno, with both candidates' messages sometimes crisscrossing.