Obama takes 50 percent support and Romney takes 48 percent among likely voters surveyed. The race is just as tight when Libertarian candidate Gary Johnson and Green Party candidate Jill Stein are included, with Obama taking 49, Romney 48, Johnson 4, and Stein 1.

The CNN-ORC poll was the third survey of Colorado released Thursday, with two of them showing Obama in the lead. Obama leads 49 percent to 48, according to a CallFire survey, and Romney leads 50 percent to 47, according to a Rasmussen survey.

Colorado is one of the closest swing states. Obama leads Romney by less than 1 percentage point, according to the RCP average.

Obama won the state in 2008, but it was only the second time since 1968 it had gone for the Democratic presidential candidate.