By Rachel Kapochunas, CQ Staff

Freshman Republican Rep. David Davis of Tennessee’s 1st Congressional District lost his seat in Thursday’s primary election, as Johnson City Mayor Phil Roe scored a narrow victory.

The upset, which avenged Roe’s loss to Davis in a crowded 2006 open-seat primary, came in a contest that was overshadowed by the Democratic primary across the state in the black-majority, Memphis-based 9th District. That is where freshman Democratic Rep. Steve Cohen , who is white, ended up easily fending off a vitriolic, racially freighted challenge by businesswoman Nikki Tinker — whose attack ads drew national attention to the contest but also spurred a backlash that appeared to undermine her campaign. Cohen led the primary in late returns with 79 percent of the vote to Tinker’s 19 percent.

In the lower-profile contest in the eastern 1st District, the Associated Press called the race around midnight Eastern time. Roe won by 50 percent to 49 percent, a margin of 460 votes according to results posted on the Tennessee secretary of state’s Web site.

Unlike most incumbents, Davis did not enter this year’s primary with a prohibitive advantage based on his previous election’s results. When Davis, a state House member and health care business owner, entered the 2006 race to succeed retiring Republican Bill Jenkins, he was one in a very crowded field of 13 GOP candidates and took the primary — tantamount to winning the seat in this heavily Republican district — with just 22 percent of the vote. Roe, the longtime mayor of Davis’ hometown of Johnson City, ran fourth in that contest with 17 percent.

But this time Roe got a virtual one-on-one shot against Davis, with only little-known candidate Mahmood “Michael” Sabri joining them on the ballot. With the major candidates evenly matched on issues and both holding strongly conservative views that reflect those of most district residents, Roe hit out hard at Davis, labeling him ineffective and accusing Davis of being in the pocket of special interests such as big oil companies. Roe pledged to refuse political action committee money.

Davis earned support from Republican groups such as the House Conservatives Fund and high-profile lawmakers such as Tennessee Sen. Lamar Alexander , and accused Roe of lying about his record.

Roe is heavily favored to win in November, with CQ Politics rating the race as Safe Republican.

Cohen, on the other hand, shrugged off suggestions that he faced a highly competitive challenge from Tinker to win the 9th District Democratic primary by a landslide margin.

The outcome contrasted with Cohen’s plurality win in the 2006 primary for the 9th District seat that five-term Democratic Rep. Harold E. Ford Jr. left open for a Senate bid that he narrowly lost. Cohen, a Jewish state senator with a liberal record and a history of rapport with black constituents, topped a field of 15 candidates in that contest with 31 percent.

But Tinker, who finished second with 25 percent, and some other black activists charged he won only because he was the only major white candidate in a field that had several significant African-American candidates, and said the seat should be returned to the black representation that had been provided by Ford for 10 years and by his father, Harold Ford Sr., for 22 years before that.

Yet Tinker, who made that argument central to her bid to oust Cohen this year, appeared to overplay her hand with controversial campaign ads that caused a surge of rebukes going all the way up the political line to presumed Democratic presidential nominee Barack Obama , who would be the nation’s first African-American president if elected in November.

One commercial assailing Cohen featured an image of a Ku Klux Klan member with a burning cross that drew objections from black supporters of the congressman and Jewish groups, among others. It portrayed Cohen as the only person, in his long-ago role as a local Memphis officeholder, who voted against renaming a park that memorializes and contains the remains of Nathan Bedford Forrest, a Confederate general who helped establish the KKK. Tinker’s critics, including those who note that many Klan members also have expressed hatred for Jews, said nothing in Cohen’s background justified the Klan imagery in the ad.

Another commercial attempted to weaken Cohen’s appeal among black constituents by implying that he was not respectful of their Christian faith, accusing him of voting as a state senator against school prayer but showing up at churches to participate in their services.