PPP said the telephone poll of Colorado residents who called themselves likely voters, conducted Oct. 16-18, found 50 percent of respondents support the Democratic incumbent versus 47 percent for the Republican challenger. Three percent of respondents said they remain undecided.
"Barack Obama still has the lead in Colorado but it's a tenuous one," said Dean Debnam, president of Public Policy Polling. "The race is the closest it's been all year and it's trended in Mitt Romney's direction over the last month."
The poll indicates Obama has a 51 percent to 42 percent lead among independent voters and a 51 percent to 46 percent advantage among voters under the age of 65. However, voters over the age of 65 prefer Romney 55 percent to 43 percent, the poll indicates.
The poll had a margin of error of plus or minus 3.1 percentage points.