NASHVILLE (AP) — A new television ad by Republican U.S. Sen. Lamar Alexander directly targets Democrat Gordon Ball as being beholden to President Barack Obama's agenda.

Unmentioned in the spot is that Alexander in a previous race sought out the endorsement of Ball — a move that the Democrat has since called a "huge mistake."

In the new ad, the narrator derides Ball, a Knoxville attorney, as a "slick talking personal injury lawyer," and returns three times to the theme that Ball would be another vote for Obama, whose presidency comes to an end two years into the next six-year Senate term.

Ball has launched his own ad featuring old footage of Alexander accompanied by an off-key version of the "Tennessee Waltz." The ad suggests Alexander is "out of tune" with Tennessee voters.