A CNN / AP poll finds Republican Cory Gardner is leading Democratic Sen. Mark Udall , 50 - 46 . Gardner , meanwhile , is viewed favorably by 50 percent of likely voters , with just 42 percent saying their opinion of him is unfavorable . Gardner 's campaign is based on huge advantages in Denver 's suburbs and Colorado 's rural areas . Gardner is one of a handful of Democratic incumbents that Republicans have targeted this year .
A CNN / AP poll finds Republican Cory Gardner is leading Democratic Sen. Mark Udall , 50 - 46 . Gardner 's campaign is based on huge advantages in Denver 's suburbs and Colorado 's rural areas . Gardner is one of a handful of Democratic incumbents that Republicans have targeted this year .