(CNN) - Earlier this year Republicans were hoping to win back both a Senate seat and the governor's office in Colorado, but thanks to divisions in the GOP, a new poll suggests that the governor's office may be out of reach.
According to a CNN/Time/Opinion Research Corporation survey released Wednesday, 47 percent of likely voters in Colorado support Denver Mayor John Hickenlooper, the Democrat's gubernatorial nominee, with 21 percent backing GOP nominee Dan Maes, and 29 percent supporting former Rep. and 2008 GOP presidential candidate Tom Tancredo, who is running as the American Constitution Party's nominee.
Maes, who enjoys the backing of some in the Tea Party movement, narrowly beat former U.S. Rep. Scott McInnis in the GOP primary last month despite several campaign controversies. After his victory, he faced calls by many prominent Republicans in his state to step down, and national Republicans seem to have washed their hands of the race.
"Maes is still winning among Colorado Republicans, with 48 percent to 38 percent for Tancredo and 10 percent for the Democratic candidate. But Tancredo has an edge over Maes among conservative voters," says CNN Polling Director Keating Holland. "So even though Hickenlooper is under 50 percent overall, he still has an 18-point lead among all likely voters."
Among those who called on Maes to step down from the nomination was Ken Buck, Colorado's GOP Senate nominee.
According to the survey, Buck leads 49 to 44 percent over Democratic Sen. Michael Bennett among likely voters, with seven percent undecided or backing other candidates. Buck's five point advantage is within the poll's sampling error.
The poll indicates Buck leads Bennett by 14 points among independent voters, while Bennet holds a five point advantage among voters 50 and older, who tend to make up a larger percentage of the electorate in midterm elections than they do during presidential election years.
The survey also suggests a geographic divide and a gender gap.
"Bennet's problem is that his support disappears the further you get from Denver," Holland says. "Bennet has a huge lead in Denver and Boulder, but the race is close in the Denver suburbs. Move further along the Front Range - the strip of fast-growing communities that strech out along the eastern edge of the Rocky Mountains - and Buck's lead widens to 18 points. Buck also has a 20-point lead in the rest of the state."
While Buck leads with likely voters, among the larger pool of all registered voters, Bennett holds a 47 to 44 percent advantage, with nine percent unsure or backing other candidates.
"As in most midterms, higher turnout helps Democrats and lower turnout helps Republicans," says Holland. "Add to that the fact that Republicans are now the party that is fired up and ready to go and the result is a group of likely voters that in most states is much more Republican than the larger pool of registered voters."
Buck, the Weld County district attorney, was once a long shot in the battle for the GOP nomination, but thanks in part to support from some in the Tea Party movement, he defeated former Lt. Gov Jane Norton, who was recruited to run by national Republicans and was the early favorite in the race.
Bennet survived a spirited Democratic primary challenge from former Colorado House Speaker Andrew Romanoff. He was appointed early last year to replace Democratic Sen. Ken Salazar, who stepped down to serve as Interior Secretary in the Obama Administration.
The CNN/Time/Opinion Research Corporation poll was conducted September 17-21, with 1,334 registered voters in Colorado, including 860 likely voters questioned by telephone. The survey's sampling error is plus or minus 2.5 percentage points for registered voters and 3.5 percentage points for likely voters.
–CNN's Deputy Political Director Paul Steinhauser contributed to this report.