A trio of House races in Tennessee [3] will keep observers’ eyes locked on the state Friday as voters head to the polls in the state’s congressional primary elections. Of course, we’ve been tracking the races as part of our Wiki the Vote [4] project, and Congresspedia [5] readers like yourself are adding details to the project every day.

Rep. Steve Cohen [6] (D), representing the 9th congressional district, has been under attack in his majority-black district. Challenger Nikki Tinker [7] has hit Cohen hard in a recent campaign commercial by running the congressman’s picture beside an image of Ku Klux Klan founder Nathan Bedford Forest. The ad takes Cohen to task for his vote, while a Center City commissioner, against renaming a park that was named after Forest.

Cohen has countered the attack by highlighting his Jewish heritage, and his recent sponsorship of legislation in the House to apologize for slavery.

(Click through for more on the congressional primaries)

Cohen is a freshman representative, as is another embattled incumbent, Rep. David Davis [8] (R). In the 2006 primary, Davis was one of five GOP candidates in the 1st CD vying for the open seat of retiring Rep. Bill Jenkins [9]. This year, Davis’s only Republican competition comes from Johnson City Mayor Phil Roe [10] (who also ran in 2006).

Davis had an early lead in the race, but Roe has since attacked the incumbent for ties to special interests.

Local media is reporting a close Republican primary in the 7th district, though coverage also indicates the race has been a quiet one. Rep. Marsha Blackburn [11] holds a vast financial advantage, but challenger Tom Leatherwood [12] said he has widespread support in the western portion of the district, where about 50 percent of the voters reside.

Of course, not all the action is in House races – seven Democrats are trying to capture the nomination to challenge Sen. Lamar Alexander [13], who was bumped up to chair of the Senate Republican Conference in the leadership shakeup after Sen. Trent Lott [14] resigned.

The Democrats in the Senate race include Mark Clayton [15], Gary Davis [16], Ken Eaton [17], Chris Lugo [18], Lenny Ladner [19], Mike Padgett [20] and Bob Tuke [21].

Stay tuned for the breakdown of the winners. We’ll also have results from Tuesday's primary elections in Kansas [22], Michigan [23], and Missouri [24].

And, as always, please check in with our Wiki the Vote [4] project for all the latest on congressional campaigns countrywide.