KIRK SIEGLER, BYLINE: As Colorado has become more diverse and urban, Republicans have suffered bruising losses in recent elections, but this year Rep. Congressman Cory Gardner is trying to capitalize on President Obama's unpopularity in his bid to unseat incumbent Dem. Senator Mark Udall. It's a race that could determine whether the GOP regains control of the Senate.
CONGRESSMAN CORY GARDNER: Let's get it done. Let's win right here in Arapahoe County.
SIEGLER: Gardner rallied his volunteers outside his campaign headquarters today in the Denver suburbs.
GARDNER: Colorado will be the tip of the spear, the fulcrum of power, the opportunity to change this direction around.
SIEGLER: The airwaves here are flooded with ads showing a beaming and energetic Gardner with his young family. Gardner won an endorsement from The Denver Post. This will be Colorado's first ever all mail-in election and the GOP has a wide lead in ballots cast so far.
CATHY HOLDERITH: Yes, is Judy there please? Do you know if she's turned in her ballot yet?
SIEGLER: At this phone bank in the suburban battleground of Jefferson County, volunteer Cathy Holderith says Gardner is energizing the base and appealing to moderates.
HOLDERITH: The strategy is Corey. He is the Energizer Bunny. He is so positive about our state.
SIEGLER: Gardner had a reputation as a hard-line conservative in the state legislature and in Congress, but he's been running the middle in this campaign and Colorado independents typically outnumber Republicans or Democrats.
SENATOR MARK UDALL: By the way, I'm proud to stand with Colorado's women. I'm proud to stand up for reproductive freedom.
SIEGLER: Campaigning in liberal Denver over the weekend, Sen. Mark Udall kept up his main strategy of painting Gardner as an extreme anti-abortion Republican.
UDALL: My campaign has been based on creating the contrast between my record on which I'm running and his record which he's running away from.
SIEGLER: Udall is confident that Democrats' late hour ground game will work, as it did in 2010 when Sen. Michael Bennet won a surprise upset here in an otherwise Republican year.
Kirk Siegler, NPR News, Denver. Transcript provided by NPR, Copyright NPR.
