THORNTON, Colo. (AP) – On the final day of Senate campaigning, both Colorado candidates concentrated where the most votes are – along the Front Range.

Democratic Sen. Michael Bennet and Republican Ken Buck hit the Denver suburbs, Fort Collins and Colorado Springs Monday on the eve of a close election.

Both stopped by phone banks of volunteers to rally supporters.

“Don’t stay up late – we’re gonna win,” predicted a confident Buck before greeting a dozen volunteers in the northern Denver suburb of Thornton.

A few blocks away, Bennet shook hands with about the same number of clapping supporters who took a break from calling Coloradans who still haven’t voted.

Bennet seemed a lot less confident than Buck, at one point even apologizing to the volunteers for being tired. But he won applause as he urged them to soldier on and try to scratch out a win when many polls predict losses for incumbent Democrats.

“We’re not giving in to the idea that we’re not going to get this done in Colorado,” Bennet said.

Volunteers at the two camps seemed as different as the candidates, though both camps were fueled by coffee and piles of leftover Halloween candy.

At a Bennet volunteer office, 52-year-old nurse LuAnn Lind says she’s been volunteering for Democrats for years and is having a harder time firing up likely supporters.

“It’s a little less urgent among the people I’m talking to,” Lind said. “I’m telling them, ‘We don’t want to lose ground now. We want to keep the Obama momentum moving forward.'”

Asked about Bennet’s chances, Lind was circumspect. “I think there’s a chance he’ll hang on,” she said.

Republicans down the street seemed surer about their chances in the Senate race. A retired elementary school teacher who was calling voters, 66-year-old Thornton Republican Susan Nalbone, said there’s a big difference between this year and two years ago, when she also called voters. In 2008, she said, Republicans were a bit dispirited.

“This is more intense,” Nalbone said. “I know that elections are all important, all a big deal, but this one feels especially important to people.”

Colorado elections officials reported Monday that more than 1 million Coloradans have already cast their ballots. In the final pre-election tally of people who cast ballots early, Colorado’s secretary of state reported that about 45 percent of all active voters have turned in ballots.

Republicans maintained their ballot lead, turning in about 445,000 ballots – almost 62,000 more than Democrats. Unaffiliated voters trailed Democrats and Republicans with about 258,000 votes cast.