DENVER -- The Democrats running for Colorado's open U.S. Senate seat will debate this week.

State Attorney General Ken Salazar and El Paso educator Mike Miles are set to debate on Friday. You can hear the candidates face off live on KCOL-radio in Fort Collins from 9 a.m. to 10 a.m.

According to a new poll, Salazar leads the candidates in the race.

If the election were today, 47 percent of survey respondents said they would choose Salazar, a Democrat, while 40 percent would choose Republican businessman Peter Coors in a head-to-head matchup. When the matchup was with Republican Bob Schaffer, about 49 percent chose Salazar while 35 percent chose Schaffer.

The survey of 800 registered Colorado voters was conducted by Mason-Dixon Polling & Research Inc. for The Denver Post from June 15-18 and had a margin of error of 3.5 percentage points.

The poll showed Schaffer and Coors both would beat Miles in head-to-head matchups if the election were today. Coors had 45 percent support to 30 percent for Miles, while Schaffer had 43 percent support to 29 percent for Miles.

"Salazar's lead now doesn't guarantee anything in November," said Eric Sondermann, a Denver political analyst. "It means that he will remain one of the most highly targeted, if not the most highly targeted, Democrats in the nation.

"It means that money and support will flow like a river right up to November."

The primary to determine who will ultimately appear on the ballot is Aug. 10. Republican incumbent Ben Nighthorse Campbell is retiring from the Senate.

At the Democratic primary, Miles will be listed above Salazar on the ballot after pulling off an upset victory over Salazar at the state Democratic assembly in May.

But the poll showed that nearly one-third of 300 likely Democratic primary voters who were surveyed had never heard of Miles, a former Army Ranger and diplomat. Still, 24 percent of Democrats surveyed had a favorable opinion of him.

Salazar, meanwhile, earned a 62 percent favorable rating from likely Democratic primary voters, while 8 percent didn't know him.

In the primary contest, 61 percent in the poll supported Salazar, while Miles got 15 percent; 24 percent were undecided. The margin of error was 6 percentage points.

The Republican race is apparently much closer. Among 300 likely Republican primary voters, 39 percent of survey respondents chose Coors to 35 percent for Schaffer. Twenty-six percent were undecided. The margin of error was 6 percentage points.

"That race is skewed more toward the conservative elements of the party," said Brad Coker, with the Mason-Dixon Polling firm. "The question for Schaffer is, will he be able to match Coors dollar for dollar? But Schaffer has strong support from party activists, so Coors has to run the table with everyone else."

Seven percent of Republicans in the poll said they didn't know Coors; 19 percent didn't know Schaffer.

As of this spring, there were 1,049,607 registered Republicans in Colorado, 863,963 Democrats and 923,532 listed as unaffiliated with either party.