Rep. John Tanner (D-Tenn.) is the second targeted Democrat in a little more than a week to announce his retirement from Congress.

Tanner said in a statement Tuesday that he considered retiring before, but he wanted to serve a term as president of NATO's Parliamentary Assembly.

"We believed we owed it to our country to stay and fulfill this term of office as NATO PA President," Tanner said in a statement. "This mandate expires in November 2010, and therefore, we have made the decision not to seek re-election to Congress."

Tanner joins Rep. Dennis Moore (D-Kan.) in becoming the first two House incumbents this cycle to not seek reelection in 2010 and also not seek another office. Moore announce his decision last weekend.

Republicans landed a surprisingly well-funded challenger to Tanner in the third quarter, with farmer and gospel singer Stephen Fincher coming out of nowhere to raise more than $300,000 for the race. Instantly, Tanner became one of the GOP's top targets nationwide and faced more reelection pressure than he has received in several election cycles.

Tanner had plenty of money for the race -- nearly $1.4 million as of Sept. 30 -- but he wasn't raising money near the clip that Fincher was.

Both Tanner and Moore are Blue Dog Democrats representing conservative-leaning or swing districts, and both districts will vault to the top of the list of potential GOP takeovers.

Republicans were immediately bullish about their prospects in West Tennessee.

"Stephen Fincher’s impressive candidacy was already raising eyebrows from Frog Jump to Washington, and we’re confident he’ll have the privilege of representing Tennessee’s 8th district after he beats whichever sacrificial lamb Democrats offer up," NRCC spokesman Andy Sere said.

Tanner was unopposed last year, but Sen. John McCain (R-Ariz.) carried his district 56-43.

This post was updated at 7:25 a.m.