NASHVILLE, Tenn. -- Tennessee U.S. Rep. John Tanner will retire next year after 11 terms in Washington.

Video: Tanner’s Retirement Announcement Shakes Tenn. Politics

Tanner was first elected to the 8th district representing rural northwestern Tennessee in 1988 and has not faced a serious challenge since.

Republicans claim Tanner's departure is due to a potentially tough re-election race next year, as the GOP targets Democrats in rural districts.

Early Wednesday morning, State Sen. Roy Herron announced he will run for Tanner's seat.

In a statement, Herron said, "Given the challenges facing this nation, this state, and this congressional district, I feel like I can help make a difference by serving in Congress.

Herron told the Associated Press he was dropping out of the 2010 Tennessee governor's race for the congressional campaign.

"In the morning, instead of campaigning in 95 counties, I'll be focused on the counties in the 8th Congressional District," the AP reported Herron said.

Herron's own press release early Wednesday morning stated, "You deserve a much fuller explanation of my decision than I can give at this late hour. I will be back in touch with you soon to share more. For now, I respectfully ask for your consideration, your support and your prayers."