In the Democratic wave of 2006, Republican Rep. Marsha Blackburn won 66% of the vote in Tennessee's Seventh Congressional District. But this year, a new poll shows, Blackburn could be in serious jeopardy against a Shelby County Register who looks like he's giving the three-term congresswoman a run for her money.

The only difference is that Blackburn and her opponent, Tom Leatherwood, will face off in the August 7 Republican primary instead of in November.

The survey, conducted by Ethridge and Associates for Leatherwood's campaign, polled 300 likely voters between 6/28-29 for a margin of error of +/- 5.6%. Leatherwood and Blackburn were tested.

Primary Election Matchup
Blackburn...........48
Leatherwood.....37

Eleven points may not seem close. But for a three-term veteran who is seen as a rising star in the House -- after losing a battle for Conference Chair, she holds leadership positions at both the National Republican Congressional Committee and the Republican Study Committee -- that's not a comfortable margin, and it's certainly not the 27-point margin by which Blackburn led in Leatherwood's previous poll, in March.

Leatherwood faces a seriously uphill climb, though. The Seventh District spans from the Memphis suburbs and Shelby County, where he serves as Register after being a State Senator, east along the Mississippi border before climbing into a Y-shape to include Clarksville, on the northern border with Kentucky, and the county south of Nashville, in the middle of the state. Reaching that many voters in such far-flung destinations is going to be a challenge.

Still, Blackburn won her original primary, in 2002, by being the only candidate from the Nashville area, while others split the suburban Memphis vote. Now, with just one opponent from Memphis, she may have reason to worry. And while finance reports released tomorrow will shed light on just how serious a foe Leatherwood is -- he reported raising just $25,000 through the end of March -- poll numbers with a month to go make it look like he's got a shot.