Sex and ethics? What's that?

Carl Hulse has an article in The New York Times about the fall of Senator John Ensign, a Republican from Nevada:

Senator John Ensign, the two-term Nevada Republican caught up in a sex and ethics inquiry, announced Monday that he would not seek re-election in 2012 to avoid what he predicted would be an “exceptionally ugly” campaign.
“As I have learned through the mistake that I made, there are consequences to sin,” Mr. Ensign, 52, said at a news conference in Las Vegas as his wife, Darlene, stood at his side.
Once considered a future presidential contender, Mr. Ensign has seen his political fortunes plummet since he admitted in 2009 to an affair with a former campaign staffer who was also the wife of a top aide. A Senate Ethics Committee investigation, still under way, began after disclosures that Mr. Ensign’s parents paid $96,000 to the aide, Douglas Hampton, who also said the senator had helped him line up lobbying clients after Mr. Hampton left his Senate job.
Mr. Ensign, who had previously insisted he intended to run again, is the eighth senator and third Republican to announce that he will not be on the ballot in 2012, a reflection of the turbulent political atmosphere and frustration some lawmakers feel about the inability to find consensus in a highly partisan Congress. More retirements are likely, freeing some senators from typical political considerations as they face tough decisions about federal spending and the deficit.
Mr. Ensign’s decision opens the door to another high-profile Senate race in Nevada, where Senator Harry Reid, a Democrat who is the majority leader, was able to hold off a strong challenge last November.
Republicans were relieved by Mr. Ensign’s decision, viewing him as badly damaged politically by the disclosures about the affair. Among Republican contenders, Representative Dean Heller had been readying a campaign, even if Mr. Ensign ran again, and is considered the current front-runner. Sharron Angle, who lost to Mr. Reid last year, has also been mentioned as a potential candidate for the Ensign seat, though she could also seek Mr. Heller’s House seat. Among Democrats, Representative Shelley Berkley is a likely contender, and other names were being floated Monday.
Federal prosecutors announced last December that they would not pursue criminal charges against Mr. Ensign, a move that surprised some Congressional watchdogs, who said the Senator’s work to line up lobbying contracts for Mr. Hampton might have violated federal law covering contacts between lawmakers and former staff members.
But the Senate ethics investigation of Mr. Ensign is expected to continue as long as he remains in the Senate. One Senate official said Monday that the committee was moving as quickly as it could to resolve the matter. Last month, the committee announced that it had appointed a special counsel to help with its investigation, an indication that it was serious in pursuing the matter and might be preparing to file formal charges.
Daniel J. Albregts, a lawyer for Mr. Hampton, said his client had no comment on the Senator’s decision to retire.
Appointing a special counsel to investigate a sitting member of the Senate is relatively rare for the Ethics Committee. Two senators who faced similar investigations in the early 1990s— Alan Cranston, Democrat of California, and David Durenberger, Republican of Minnesota— both chose not to run for re-election after the special counsel completed his report. Mr. Cranston was reprimanded, and Mr. Durenberger denounced for their dealings with a savings and loan executive.
Carol Elder Bruce, the special counsel in the Ensign inquiry, is an experienced former federal prosecutor who previously served as an independent counsel investigating Bruce Babbitt, the interior secretary during the Clinton administration, and before that, a top aide in the inquiry of Edwin Meese III, attorney general under President Ronald Reagan. The committee recently interviewed Senator Tom Coburn, Republican of Oklahoma and a former housemate of Mr. Ensign, who counseled his colleague after learning of the affair.
Mr. Ensign moved last year to set up a legal defense fund, sending out a letter to supporters urging them to help defend him against what he said was an investigation inspired by liberal activists. Mr. Ensign said that he was driven to leave Congress, not by the pending Ethics Committee inquiry, but by the potential personal cost to his family of a campaign that would no doubt focus heavily on his past actions. “I don’t want to put my family through that,” he said.