Ten years ago today former chief White House domestic adviser John D. Ehrlichman was testifying before the Senate Watergate Committee and many Americans were, as they would be for that entire summer, glued to their television sets.

The Senate Watergate hearings--or more precisely the hearings on television, which ran from late May until August of 1973 and then resumed in the fall--were Richard Nixon's undoing as president. The hearings provided a platform for Nixon's chief accuser, former White House counsel John W. Dean III. Dean revealed a laundry list of sordid and seamy things done in the Nixon White House, made public Nixon's and his aides' contempt for constitutionally protected rights, and also disclosed the existence of the evidence that ultimately drove Nixon from office--the White House tapes. Television was uniquely suited to bringing the event home, literally and figuratively, to the American public.

Tonight, the two-hour "Summer of Judgment: The Watergate Hearings" (Channel 26 at 9) commemorates those hearings, airing excerpts from them along with recent interviews with some of the men who sat across the table from the parade of witnesses.

Moderator Charles McDowell, Washington correspondent for the Richmond Times-Dispatch and a frequent panelist on "Washington Week in Review," is appropriately serious and reflective in laying out what he calls the "darkest passage in American politics."

Of the seven senators on the committee committee chairman Sam J. Ervin Jr. (D-N.C.), Democrats Herman E. Talmadge (Ga.), Daniel K. Inouye (Hawaii), Joseph M. Montoya (N.M.) and Republicans Howard H. Baker Jr. (Tenn.), Edward J. Gurney (Fla.) and Lowell P. Weicker Jr. (Conn.) , only Inouye, Baker and Weicker still are in the Senate. Ervin, who became something of a folk hero for his down-home and passionate defense of the Constitution during the hearings, is interviewed, as are Weicker and Inouye. Baker reportedly declined interview requests. Former chief committee counsel Samuel Dash, chief minority counsel Fred D. Thompson and assistant chief committee counsel Terry F. Lenzner also appear in excerpts and in recent interviews.

As a nostalgia piece for Watergate junkies, "Summer of Judgment" works all right. As an attempt to recapture the drama of that summer 10 years ago, however, it falls short of the mark. Part of the problem is the choice of a moderator. However engaging McDowell may be while batting around the week's developments with colleagues on camera, he is too low-key for this role.

Although it's probably not McDowell's fault that he is on camera as much as he is, time and again during the two-hour presentation the drama is drained from the events by McDowell's telling what happened instead of showing it. Former White House chief of staff H. R. (Bob) Haldeman startled the committee and everyone else in the Senate Caucus Room when he told the committee in his opening statement that he had listened to the White House tapes at the same time that Nixon was denying the committee access on grounds of executive privilege. Rather than showing Haldeman's testimony, McDowell merely refers to it.

When former White House aide Alexander P. Butterfield's testimony revealing the White House tapes is presented, the moment is deprived of any bite by the five minutes or so of background that precede it.

The last 15 minutes of the program are taken up with excerpts from the House Judiciary Committee's impeachment proceedings in July 1974 and a summation by Stephen Hess, briefly a Nixon White House aide in 1969 and now a senior fellow at the Brookings Institution.

Surely the historical record, video version, would have been better served by at least a mention of, if not an excerpt from, Nixon's announcement in April 1974--a desperate effort to head off disaster--that he was releasing transcripts and tapes of some of the conversations.

In any case, those who can never get enough of Watergate can tune in to "Summer of Judgment" and wallow in ecstasy for two hours, and those who were too young to know can get at least a rough idea of what all the furor was about.