With today marking the 20th anniversary of the House of Representatives vote to impeach former President Bill Clinton, far too many people don’t remember or understand why and how it all happened.

The popular mythology usually goes no further than the idea that “Clinton was impeached for adulterous sex with an intern.” The slightly more sophisticated version is that he was impeached for lying about sex with the intern, Monica Lewinsky. Even with that understanding, most people don’t know why an independent counsel was asking Clinton about sex in the first place.

The real story is that the heart of the case stemmed from ongoing efforts to obstruct justice. (The second successful impeachment count, and the most important, was for obstruction.) Furthermore, it was the obstruction efforts themselves that provided the nexus between Clinton’s sexual escapades and the long-running, quite legitimate, investigation into his finances.

It went like this: The Clintons were surrounded by allegations of scandal, some more real than others, from their long exercise of power in Arkansas. Among those imbroglios was an interlocking set of bad investments in real estate speculation and banking that, as they failed, led to illegal activity while attempting to escape the losses. Failure of those financial institutions cost U.S. taxpayers $73 million. Fifteen people, including Arkansas Gov. Jim Guy Tucker, eventually were convicted of 40 crimes.

Prosecutors drafted several indictments against Hillary Clinton, but they decided the complicated cases were unlikely to convince a unanimous jury to convict a sitting first lady.

In the course those numerous scandals, Bill Clinton allegedly misused public resources, repeatedly, to cover up misdeeds big and small. Among these many practices were the alleged use of state troopers to help him procure, and hide, his voracious adulteries.

Amid the whole tangled web, investigators began seeing the multitudinous scandals and cover-ups as part of what amounted to a significant criminal conspiracy. Some of the same people covering up the financial shenanigans were covering up the trysts, with threats or illegal inducements allegedly emanating from the same inner circle against potential whistleblowers about misdeeds both physical and financial.

When private lawsuits related to sex were filed against Clinton, they touched on the same sort of potentially illegal obstruction of justice. U.S. Attorney General Janet Reno asked independent counsel Kenneth Starr to expand his investigation by examining those allegations too.

When one of the sex-related lawsuits listed Lewinsky as a Clinton paramour, presidential associates, including prominent Democratic power broker Vernon Jordan, jumped into action at Clinton’s behest to try to find Lewinsky a job at the United Nations. The modus operandi was similar to those allegedly used in other Clinton cover-ups: Use public resources or executive influence to provide a mix of lures and pressure — whatever worked best, whether carrots or sticks — to keep somebody from spilling the beans, or to convince them to lie if questioned by investigators. The latter effort, if it happened, is illegal subornation of perjury.

Starr’s team sensibly saw these seemingly long-running, multi-faceted cover-ups as the equivalent of racketeering, all involving a mens rea, or “state of mind,” that showed consistent criminal intent. So, when in pursuit of its mission as defined by Reno, Starr’s team interviewed Clinton about Lewinsky, the questions about the affair were directly material to the whole issue of obstruction and conspiracy.

When Clinton lied under oath about that, and directed others to lie, he by ordinary standards had committed perjury and criminal obstruction of justice. The House, acting as the equivalent of a grand jury issuing the constitutional equivalent of indictment of a president, was right to impeach him.

The Senate’s job, in later deciding Clinton’s misdeeds didn’t meet the constitutional standard of “high crimes and misdemeanors” required to remove a president from office, involved different considerations entirely. Starr’s team had done the job with which it was tasked by the attorney general, and the House carried out its duties appropriately. The sex had never been the real issue; the issue was the public corruption.