Colorado voters don't much approve of Sen. Michael Bennet (D). On the bright side for him, they don't think much of his potential Republican opponents either.

A new survey from Public Policy Polling (Aug 14-16, 969 LV, MoE +/- 3.2%) finds 38 percent disapproving of the job Bennet is doing, with just 31 percent approving -- lower but not far from his numbers in April. Former Rep. Bob Beauprez, who's considering a bid and is the most well-known of the three GOPers tested against Bennet, is seen unfavorably by 40 percent of voters, with 30 percent holding a favorable view of him.

Already running are Weld County District Attorney Ken Buck and Aurora Councilman Ryan Frazier. Buck gets a 18%/19% favorable rating, and Frazier's is 11%/19%. Not tested was former Lt. Gov. Jane Norton, who the Denver Post reports will decide whether or not to run within the next month.

Bennet holds small leads over Buck and Frazier, but trails Beauprez -- who lost the 2006 gubernatorial race by 17 points.

Bennet 39 - Beauprez 42 - Und 19

Bennet 39 - Buck 35 - Und 26

Bennet 38 - Frazier 33 - Und 30