The Keating Five "trial" before the Senate Ethics Committee is not a pretty sight. Courtesy of C-Span, the ugly spectacle is there for the whole nation to see and hear -- not in 20-second bites but hour after hour. It is a humiliation not just for five misguided senators but for the Senate itself.

The five accused senators sit, taut and uncomfortable, each accompanied by a clutch of lawyers. They wince as special counsel Robert S. Bennett charges they intervened improperly with federal regulators on behalf of Charles H. Keating Jr., who contributed more than $1.3 million to their political campaigns.

Keating's defunct Lincoln Savings and Loan Association of Irvine, Calif., was seized by federal authorities last year. The estimated $2 billion bailout has become a symbol of the larger S&L debacle, which could cost taxpayers $500 billion before it's finished.

Bennett said that of the five, three were deeply involved with Keating: Dennis DeConcini (D-Ariz.), Alan Cranston (D-Calif.) and Donald W. Riegle Jr. (D-Mich.). According to Bennett, the other two -- Sen. John Glenn (D-Ohio) and John McCain (R-Ariz.) -- pulled out early, once they learned that Keating was likely to face criminal charges.

But the scandal has enmeshed and scarred them all. As Ethics Committee chairman Howell Heflin (D-Ala.) put it to them in a blunt opening statement: "Many of our fellow citizens apparently believe that your services were bought by Charles Keating, that you sold your office, that you traded your honor and your good name for contributions and other benefits."

The impassioned, emotional defense by all five senators had a common theme: They did nothing wrong and certainly nothing that all other senators (including members of the committee) don't regularly do to help their constituents and political contributors.

But Bennett insists that what the Keating Five did was the exception, not the rule -- that the standards were clear, but that DeConcini, Cranston and Riegle failed to observe them. He accused DeConcini of being the chief organizer of a 1987 meeting the five senators held with former Federal Home Loan Bank Board chairman Edwin H. Gray to get a better deal for Keating.

In a combative and at times hysterical response, DeConcini seemed confused about the proper role of a U.S. senator. Alternately denying guilt and denouncing Bennett and Common Cause -- the citizens' lobby group that prodded the Ethics Committee to investigate the Keating Five -- as "unfair," DeConcini offered a job description of a senator as little better than a lackey for wealthy, constituent businessmen.

DeConcini boasted that his office runs a "constituent service ... on a day-to-day basis." If a constituent has a problem "with the government" (DeConcini oddly doesn't seem to be part of the government in this context), then DeConcini goes to bat for him. "They have a right to ask for our intervention," DeConcini said.

But suppose those constituents are hefty contributors to the senator's political campaign? No matter. "We intervene for them. This senator intervenes; that's my job," DeConcini said. "There's been no unethical conduct. I broke no law. I broke no statute." DeConcini's lawyer, James Hamilton, added that just because there is "a rough proximity between the service and a contribution," there is no illegal act.

It won't wash. In a moment of candor, DeConcini, blaming political fund-raising excesses rather than himself, said: "Now, I'm not saying it shouldn't be changed, gentlemen, because it should. It looks like hell. I don't like it, and I've supported campaign reform every year that I've been here."

The bottom line is that a senator is supposed to have a higher calling than running errands like a Tammany Hall ward heeler. According to the Constitution, a "United States" senator represents the entire nation, not just the parochial interests of a single state, much less those of a single constituent. DeConcini should understand he is one of two United States senators who happen to come from the State of Arizona. But he portrayed himself as a cheerleader for Arizona "constituent" interests -- an adversary of the influence of the federal government, which happens to own large amounts of land in Arizona.

No matter how shrill DeConcini's and the others' insistence that their "constituent services" are available to one and all, regardless of political contributions, the average citizen properly guffaws at the thought that he or she could get the five to go to bat the way they did for Keating.

The five senators exercised bad judgment in their relationships to Keating -- in different degrees, according to Bennett. It seems likely that whatever punishment is meted out by the Ethics Committee will hit Cranston, DeConcini and Riegle hardest.

But this week on C-Span has been costly to all five. The image of them sitting, each in his own dock to avoid any reflected taint from the others, will be hard to erase from memory. One can hope that other U.S. senators will think long and hard before risking the same exposure.