2002 Midway through his second term in the State Senate, in 2002, Davis ran for the Democratic nomination in the 4th District when four-term
Republican incumbent
Van Hilleary gave up the seat to make what would ultimately be an unsuccessful run for
governor. This time, he narrowly won the primary against a self-funding opponent, Fran Marcum of
Tullahoma, who spent nearly $2 million in the race. He went on to win a hard-fought battle in the general election, narrowly defeating Republican Tullahoma Alderman
Janice Bowling, 52%-47%; Bowling was Hilleary's district director.
2004 Davis was reelected in a 2004 rematch against Bowling with slightly less difficulty, 55%-44%.
2006 Davis faced nominal opposition in 2006. Although the 4th was not considered safe for either major party, its size (it stretches across two time zones and five television markets) made it very difficult to unseat an incumbent. Davis defeated Republican Kenneth Martin, 67.5%-32.5%.
2008 Davis did not make an endorsement of the candidate in advance of the
2008 Democratic National Convention.
Hillary Clinton won the primary in his district by a significant margin, and
John McCain outran
Barack Obama there by 29 percentage points. In the
November 2008 general election, Davis defeated Republican candidate
Monty Lankford, a hospital equipment company owner.
2010 Davis was considered a possible candidate for
Governor of Tennessee in
2010. However, he announced that he had decided not to seek that office in January 2009, and instead ran for reelection to his House seat. In the 2010 congressional race, Davis was challenged by Republican
Scott DesJarlais. Also on the ballot were independents Paul H. Curtis, James Gray, Richard S. Johnson, and Gerald York. DesJarlais won 57.1% of the vote to Davis's 38.6%--the third-largest margin of defeat for a Democratic incumbent in the 2010 cycle, the first time an incumbent had been unseated since the district's creation in 1983, and the first time since 1974 that an incumbent congressman in Tennessee lost a general election. ==Voting incident==