The resignation of Rep. David Wu may seem like little more than a blip in the year's cavalcade of sexual misconduct by elected officials, from all-male tickle parties and crotch sexting to craigslist trawling. And the swift departure of this Oregon congressman, who said a recent sexual encounter with a friend's teenage daughter was "consensual," assures his name will fade as quickly as last week's debt reduction plan.

But the Wu story, which has been followed closely by few outside the Northwest, deserves more attention. In fact, it is among the most compelling arguments for why news organizations should aggressively pursue allegations of sexual misconduct, even when they seem like ancient history.

I am a reluctant convert to the value of sex as an investigative subject. In the late 1980s, shortly after Gary Hart's infamous invitation to "follow me," led to revelations about his extra-marital canoodling aboard the good ship Monkey Business, I was asked by an editor in the New York Times Washington bureau to look into a rumor that Vice President George H. W. Bush had fathered a child out of wedlock. I refused, telling my boss that "I didn't become a journalist to peer into people's bedrooms."

A few years later, a thinly sourced version of the story surfaced in the New York Post. Bush, by then president, brushed it off. "I'm not going to take any sleazy questions like that," he bristled. "I'm not going to respond other than to say it's a lie."

Quaintly, a denial from the president put the story to rest.

A few years later, I was in Arkansas for the New York Times to interview Judge David Hale, a peripheral figure in the Clintons' Whitewater land dealings. Jeff Gerth and I repeatedly pressed Hale for details on the couple's feckless attempt to create a vacation wonderland in the Ozarks. Mystified, Hale asked Gerth, who is now a ProPublica reporter, why we weren't more interested in Clinton's sex life. Jeff explained that we were from the New York Times and didn't do sex investigations.

Fast forward to Bill Clinton's second term, and we were all galloping after the Monica Lewinsky story which, typically, had been broken by our competitors. One weekend I went to visit my brother, a lawyer who respected the sober journalism practiced by the Times. We stopped in a supermarket and I bought a copy of the National Enquirer. "You read this?” he asked incredulously. "Yes, ‘' I replied. "They've had a lot of stuff first on Monica." Thumbing through the issue, I pointed to an article about a stained blue dress. "Who knows?” I said. "This might even be true."

In 2002, I joined the Oregonian in Portland, Ore., as a managing editor. Within a year, I was part of the management team that bungled one of the most significant sex scandals one could imagine: the story of how a former governor and Carter-administration Cabinet secretary had preyed on a teenage girl and covered up his misconduct. Neil Goldschmidt was the golden boy of Oregon politics, a kingmaker with the darkest secret imaginable. We had a plausible tip on the story but failed to follow up, allowing a competitor, Willamette Week, to break the story and win a Pulitzer Prize.

It marked the second time in modern history that the Oregonian had failed on a big sex story. Earlier, the paper had known about and failed to fully investigate on Sen. Robert Packwood's habit of making unwanted sexual advances. One of his victims had been a reporter in the Oregonian's Washington bureau. The story appeared first in the Washington Post, embarrassing the hometown paper.

In the wake of the Goldschmidt story, I pushed the Oregonian's reporters and editors to run to ground every tip relating to sexual misconduct by a public official.

Our attention quickly turned to David Wu, who was running for re-election in 2004. Wu, a Taiwanese immigrant and lawyer, was an awkward man. Years earlier, the paper had been tipped that he had sexually accosted his ex-girlfriend while a student at Stanford in the mid-‘70s. Efforts to confirm the story had been unsuccessful.

We assigned three reporters to try again. The woman at the center of the case politely but adamantly refused to cooperate, saying she had long ago made her peace with whatever had happened. No charges had ever been filed. There was no paper trail of any kind.

But over several months, reporters Laura Gunderson, Dave Hogan and Jeff Kosseff improbably tracked down witnesses who were willing to go on the record. They found Leah Kaplan, an 82-year-old former therapist at Stanford who had counseled the woman and was suffering from a fatal illness. Kaplan, still angered by the incident, breached patient confidentiality and said that she had pressed Stanford officials to take disciplinary action against Wu. She said they declined to ruin the record of a promising young man who, at the time, was hoping to attend medical school.

Kaplan's statements were intriguing, but not sufficient. We pressed the reporters to find the campus security officers who responded to complaints of a woman screaming in 1976. Find the cop. He'll remember.

And so they did. Raoul K. Niemeyer, then a patrol commander at Stanford, remembered that Wu had scratches on his face and neck. He said Wu claimed that what had happened was "consensual."

Just a few weeks before the election, we had a story ready for publication. Wu hired a lawyer who ferociously counter-attacked, threatening to sue the Oregonian if any story were published. Neither Wu nor the lawyer would answer questions about the incident, but they contacted Kaplan's family and made it clear they were prepared to hold the dying woman legally accountable for her conduct. Wu's campaign manager said the candidate would never respond to "unsubstantiated allegations."

Top editors at the paper were divided about what to do. It was late in the campaign. The incident was decades old. Could one reasonably call it a "youthful" mistake? Was it fair to put someone's college years under a microscope? The victim was unwilling to come forward. Shouldn't that weigh? And what about the threats from Wu's lawyer?

Ultimately, we decided to publish. We concluded that at least some voters would want to know their congressman had this incident in his past. The morning the story appeared, Wu issued a statement saying: "As a 21-year old, I hurt someone I cared very much about. I take full responsibility for my actions and I am sorry. This single event forever changed my life and the person that I have become."

Wu's opponent hammered away at his character—to no effect. More than 350 readers wrote to criticize the story, and even the paper's ombudsman attacked it, questioning its relevance and reliance on second-hand sources.

Wu went up in the polls, winning re-election easily.

Over the next few months, we heard other stories from other women. None was willing to go on the record. It appeared to us that Wu's aggressive conduct with women may have continued deep into his adulthood. But we were unable to prove it.

The Wu story revived during the 2010 election cycle, when most of his aides quit just after the campaign. Several said his behavior was bizarre. Someone leaked a photo of the congressman in a tiger suit that he had sent aides.

Following the story from New York as an editor at ProPublica, I shrugged. And then came the bombshell disclosure that an 18-year-old woman, daughter of a political supporter, had called Wu's offices and left a voice mail stating that she had been the victim of a coercive sexual encounter with him the previous Thanksgiving.

Oregonian reporters Charles Pope, Janie Har and Beth Slovic broke the story. Once again, Wu initially refused to respond to questions. Once again, the victim declined to participate in the story. Once again, Wu said it was "consensual."

After a few more days of hanging tough, Wu took the advice of Democratic leaders and said he would resign after the debt ceiling debate is resolved. ""The well-being of my children must come before anything else," he said in a statement.

I apologize to the teenager whose distraught call is said to describe a traumatic experience at the hands of a 56-year-old member of Congress. Despite our best efforts, we failed you. Sadly, I have come to the conclusion that sex can be a legitimate arena for investigative reporting. It certainly was in the case of David Wu.