The Rise and Fall of John Ensign

John Ensign, the Nevada senator who admitted an affair with a female staffer in 2009, will retire from the Senate at the end of his current term, capping off a career nosedive that saw him fall from party star to seat ceder.

Roll Call's David Drucker reports Ensign won't run again in 2012:

Sen. John Ensign is expected to announce at an afternoon news conference in Las Vegas that he will retire rather than face a brutal 2012 re-election campaign, according to knowledgeable sources.

The fallout from Ensign's affair has been messy. After Ensign admitted to the affair in June 2009, it became apparent that Ensign had found himself in a tangled situation. He had carried on the affair with his campaign treasurer, Cindy Hampton, whose husband, Doug Hampton, also worked for Ensign as a senior aide. It was reported that Doug Hampton had attempted to extort the senator, prompting Ensign to disclose the affair. Ensign's parents, it came out the next month, had paid almost $100,000 to the Hamptons. Ensign had paid Cindy Hampton $25,000 severance.

Last January, Politico reported that the FBI had begun contacting witnesses to investigate events surrounding the affair. The Justice Department dropped its investigation of ensign in December, and Ensign avoided federal charges.

But the scandal has only dragged on, nonetheless: Just last week, the Senate Ethics Committee took depositions in its ethics investigation into Ensign's conduct.

Ensign has found himself, after all this, as a prime target for Democrats--one of those flagship campaign-season punching bags, used as fodder for Democrats nationwide as they attempt to categorized Republicans as sleazy across the country, in congressional races that have nothing to do with Ensign, in a presidential year no less. The mention of his name is enough to make some Democratic campaign-committee staffers giddy.

The scandal has brought Ensign, once a slick up-and-comer in the GOP's ranks, from the heights of influence to an exit from the political game.

Before his scandal broke, Ensign was viewed as one of the top political operators on Capitol Hill, a talented partisan strategist comfortable in his role heading the party's Senate campaign arm, the National Republican Senatorial Committee, which he took over for the 2008 election cycle after being reelected in 2006. He held a place as one of the most powerful Republicans in Washington, in constellation with the Mitch McConnells, Tom Coburns, and John Boehners in town.

As a politician, Ensign is smooth. With a polished manner, his white hair combed back, he thinks quickly and stays on message. In 2007 and 2008, he seemed to be at the top of his game--an effective mover and shaker, even in down years for Republicans.

Which is what makes his reversal of fortune so striking. Last month, after polls showed Ensign losing to Republican Rep. Dean Heller in a potential primary for his seat, Republican lobbyists in D.C. had begun a push to get party leaders (including Sen. John Cornyn, Ensign's successor at the helm of the NRSC) to force Ensign out of his own reelection race, fearing he would drag the party down across the board.

Ensign had gone from a party asset--a bright spot in rough times--to dead weight, worth casting aside even as the GOP enjoys broad national momentum.

It's the same stock tale of the political affair scandal, but where observers see the classic morals about hubris and falling from the height of power, in Ensign's case, the main character really was that high.

Drop-down image credit: Alex Wong/Getty Images