NASHVILLE, Tenn. (AP) -- Former Tennessee Democratic Party Chairman Bob Tuke has won the U.S. Senate primary to challenge Republican Sen. Lamar Alexander this fall.

Tuke is a Nashville attorney and former Marine officer who fought in the Vietnam war.

With 82 percent of precincts reporting, Tuke had more than 43,000 votes, or 30 percent. His closest opponent was Gary Davis of Nashville, a political unknown who neither spent nor raised any money during the campaign.

Davis had nearly 33,000 votes, or 23 percent. Tuke's most active opponent during the primary campaign, former Knox County Clerk Mike Padgett, had about 28,000 votes, or 19 percent.

Alexander was unopposed in the GOP primary. The Senate primary was the only statewide race on the ballot.

(Copyright 2008 by The Associated Press. All Rights Reserved.)