As Senate clock ticks, Udall traverses Colorado, Gardner scales back Colorado's Sen. Mark Udall and Rep. Cory Gardner took starkly contrasting approaches in their campaign appearances Tuesday in the waning hours of one of the most competitive U.S. Senate contests this year. Udall, a Democrat seeking a second term, traversed between three university campuses delivering speeches in a last minute effort to court young voters. Gardner made a pair of appearances - no speeches for him--with Republicans in morning honk-and-waves in the Denver suburbs. Gardner, who gave up a safe GOP House seat in eastern Colorado to challenge Udall, has led narrowly in a series of recent public polls as he looks to help turn the tide for Colorado Republicans, who have not won a Senate race in more than a decade. And he's not taking any risks. Instead of making stump speeches or seeking to persuade last-minute voters in meet-and-greets, Gardner has been much more subdued. In the past 48 hours, Udall has put hundreds of miles on his campaign bus as it has rumbled to more than a dozen locations throughout this state's populated Front Range. Not Gardner. On Monday he held just a single event, speaking briefly to volunteers at a Republican field office -- his first public appearance since Saturday. Gardner campaign aides said he's looking forward to spending time with his wife and two young children. Gardner's strategy reflects the fact that he is ahead in the polls and that Republicans lead in voter turnout. His campaign believes he is poised to win, and they want to avoid any gaffes that could harm him in the last days of the campaign," said Peter Hanson, a professor of political science at the University of Denver. Hanson added that with Udall down in the polls, visiting college campuses is a "smart way for him to mobilize students who are reliably Democratic but who may not otherwise vote." This is the first major election in which a ballot was mailed to every Colorado voter; they must be turned in by 7 p.m. Based on early ballot returns from the Colorado secretary of State's office, about 1.6 million ballots had been cast in Colorado as of Tuesday morning. Republicans outpaced Democrats 40% to 32% in ballots returned, while unaffiliated voters -- which account for about a third of registered voters here in Colorado -- represented about 27% of ballots cast. On Tuesday afternoon Udall will arrive back on the campus of Metropolitan State University of Denver where he stumped a day earlier alongside Sen. Michael Bennet and former Interior Secretary Ken Salazar in an appeal to college voters and Latinos. As Jimmy Scott, an engineering student at the nearby University of Colorado at Denver, walked along a sidewalk near Udall's campaign bus after Monday's event, he seemed unlikely to even cast a ballot Tuesday. "It's all just nonsense," Scott said when asked about the election. The radio ads, the back and forth negative ads, I don't follow politics, but it's not something that makes me want to tune in and actually vote.