Almost 40 years later, there are still unanswered questions about the 1972 Watergate break-in and cover-up.

The one that tugs at Nixon White House counsel John W. Dean is the one he posed during the 1973 Senate Watergate hearings: "How in God's name could so many lawyers get involved in something like this?"

Dean, 73, asked it anew last month in Philadelphia, at a meeting of the Pennsylvania Association of Criminal Defense Lawyers.

This time, however, Dean and program partner James D. Robenalt, a Cleveland lawyer, asked it as part of a continuing legal education course on ethics - viewed through the lens of a scandal that ended in the first resignation of a U.S. president.

Dean - Georgetown University Law Center, Class of '65 - counts himself among those "who screwed things up."

He has impressive company. Dean said he once counted 21 lawyers involved in Watergate wrongdoing, including President Richard M. Nixon, White House Domestic Affairs Adviser John Ehrlichman, Attorney General John Mitchell, Nixon lawyer Herbert Kalmbach, White House special counsel Charles Colson, and Egil "Bud" Krogh, who headed the "Plumbers" unit involved in the break-in.

More important, said Robenalt, the Watergate crimes that sent Dean and others to prison were all committed in the first week after the June 17, 1972, break-in at Democratic National Committee Headquarters.

"Everything in the scandal happened right away: 24, 48 hours, the first week. The die is cast," Robenalt said.

Said Dean, "If you could think of a mistake during a short period of time and then repeat all those mistakes again, the first week is a very ideal example. We wrote the book on what not to do."

So why is Watergate important for today's lawyers?

Dean and Robenalt cite the burgeoning scandal at Pennsylvania State University, which they said is their most-asked question.

"It will be interesting to see what the [university] lawyers did," Robenalt said.

Dean and Robenalt said it's important to understand why ethical guidelines for lawyers came to be, and the pair called those rules the enduring legacy of Watergate.

The ethics rule that a lawyer who uncovers crime or fraud within an organization must report the crime "up and out" is exactly what the Watergate lawyers did not do.

Dean was appointed Nixon's White House counsel in July 1970 at age 31. He said he thinks the White House wanted a young, ambitious lawyer for the job. He was five years out of Georgetown University and had spent time as chief minority counsel to the House Judiciary Committee.

If the title was heady, Dean found himself an outsider on the inside after the break-in. On Aug. 29, 1972, Robenalt said, Nixon announced that Dean had conducted an internal probe and cleared White House staff of any crimes, "much to John's surprise."

By the time of Dean's March 21, 1973, meeting with Nixon, in which he told the president of a "cancer on the presidency," Dean said he knew he could never stop the cover-up.

In October 1973, Dean pleaded guilty to obstruction of justice and served 120 days.

Dean left prison a celebrity. His testimony before the Senate Watergate Committee from June 25 to 29, 1973, was carried live by all three TV networks and replayed at night by PBS. Robenalt said 85 percent of American households tuned in.

His first Watergate book, Blind Ambition, was a 1976 bestseller and later a movie.

Dean did not return to law. He became a California investment banker and full-time author. His work with Robenalt, and his publisher's request for a Watergate book for the 40th anniversary, led Dean and a researcher to again listen to and catalog the 2,000 taped White House conversations about Watergate.

"Today, I know more about Watergate than I did when I lived through it," Dean joked.

But the tapes did not answer Dean's question.

"How could people who I thought were fairly intelligent men, certainly politically savvy men, make one bad decision after another?" Dean asked.

One factor was the Nixon White House's antipathy toward Congress.

"With the exception of Richard Nixon, my superiors - John Ehrlichman, Bob Haldemann, John Mitchell - were surprisingly unsophisticated about the ways and means of Washington," Dean said. "They really thought the president had powers and abilities to make things happen in the city that were not the case."

Dean also cited a "real attitude of arrogance toward the law," embodied in Nixon's famous post-resignation comment to David Frost: "When the president does it, that means that it is not illegal."

If Dean focuses on Watergate legal questions, the public won't give up on others.

Yes, Dean told the lawyers, he's still married to Maureen.

As for the 181/2-minute gap on one Watergate tape?

"The short answer to that is, it's a better mystery than ever knowing what it is. . . . The best that I can tell is there is absolutely nothing there that is of significance. It was accidentally done by Rose Mary Woods on a very, very weak machine."