A poll released Monday conducted by left-leaning Public Policy Polling is showing some separation in the wide-open GOP contest to replace U.S. Sen. Saxby Chambliss.

The poll, commissioned by the lefty guerrilla group Better Georgia, has Rep. Paul Broun of Athens at 27 percent in the GOP contest. Rep. Phil Gingrey of Marietta is at 14 percent, Rep. Jack Kingston of Savannah is at 13 percent and businessman David Perdue is at 12 percent. Former Secretary of State Karen Handel notches 9 percent in the question, which involved only those who identified themselves as GOP primary voters. About a quarter were undecided.

(Candidates Art Gardner and Derrick Grayson weren't included in the survey.)

It gets more interesting in head-to-head matchups with Democratic front-runner Michelle Nunn. Respondents had Nunn and Broun at a 38 percent deadlock, and Nunn with slight leads over Kingston, Handel and Gingrey. (A matchup between Nunn and Perdue was apparently not one of the questions.)

The poll involved 580 voters surveyed between March 5-6. Roughly half of the respondents said they generally vote in GOP primaries and 41 percent vote in Democratic contests. Some 49 percent favored Mitt Romney in 2012, compared to 43 percent who backed Barack Obama.

The five best-known GOP candidates are in a tight race to keep the Senate seats in Republicans hands. A loss to Nunn, the daughter of former U.S. Sen. Sam Nunn, would make it more difficult for the GOP to wrest control of the Senate from Democrats.

Pollsters asked about a few legislative items as well, including whether medical marijuana should be legally allowed for purchase with the approval of a doctor. About 70 percent of voters said yes, while 23 percent said no.

You can find the crosstabs below, but one of the more interesting tidbits: Nunn has leads between six percentage points to 10 percentage points among female voters in the head-to-head matchups.