The question hangs over the massive Senate hearing room where the "Keating Five" are being heard: Would five senators be in the dock if they had been caught doing favors for anyone but the S&L kingpin?

It's like the question that haunts our desert troops: Would they be there if it weren't for the oil?

The answer to both questions is: probably not, but it doesn't matter.

Both enterprises are too far launched to be canceled. Lawmakers, with the candid exception of Alan Cranston (D-Calif.), who said big contributors have much better access than non-givers, are protesting that they are at the beck and call of their constituents, that they broke no laws or Senate rules.

The Senate ethics committee has been exhibiting rather odd ethical standards of its own. It refused to drop member Jesse Helms (R-N.C.), who during the heat of his recent campaign called Cranston "the leading water-carrier for the S&L industry in Congress." Cranston sent a donation to Helms's rival and Helms has uninhibitedly displayed an urge to get even.

This was, he grumped when called on his statement, "fact -- I don't know what the problem is." Were the five in a courtroom, Helms would have been hustled out the door as a prospective juror. But Chairman Howell T. Heflin (D-Ala.) is constantly reminding everyone that this is "not a trial" and that the committee is not a judicial body. And he warns the special counsel, Robert S. Bennett, that he must present only facts, not conclusions, although he was hired to do both.

Bennett, who has been inconveniently thorough in his investigation, has become the heavy in the hearing room.

The riposte from the charged senators is "Bennett, you're no U.S. senator."

He never said he was, of course, but the best hope of Donald W. Riegle Jr. (D-Mich.) and Dennis DeConcini (D-Ariz.) -- Cranston has already said he will not run again and John Glenn (D-Ohio) and John McCain (R-Ariz.) have been virtually exonerated -- lies in convincing people that "everybody does it" (it being constituent service, often in behalf of big contributors). Bennett is Alexander Haig's Watergate "sinister outside force."

Bennett wouldn't understand, they said. He knows nothing about the rites and customs of the lodge. He doesn't belong. He was patronized, lectured, called ignorant and biased. He wants, DeConcini said, "to nail a trophy to the wall."

Bennett's previous trophy was Sen. Dave Durenberger (R-Minn.). Although judging a peer gives your average senator heartburn, Durenberger was relatively easy. None of his judges could imagine getting around the honoraria ban by writing a book and claiming speech fees as royalties.

But the activity the Keating Five have described are the kinds of things senators do every day. When he got a chance to answer back, Bennett said that Potomac School, attended by his daughters, has an ethics code and enforces it, something he thinks the world's greatest deliberative body can emulate.

The senators seemed invigorated by the chance to defend themselves. Several brought visual aids. Cranston, who is 76 and sick with cancer, had charts showing that all his brother lodge members have fund-raisers on their staffs. He warned they could find themselves in the dock for battling bureaucrats in behalf of constituents. He never mentioned Charles H. Keating Jr., who gave him almost a million dollars. Cranston used it to further, indirectly, his ambition to be a senator forever -- funding a nonpartisan registration drive that inevitably brought more Democrats to the rolls.

Riegle, who followed him to the dock, had the animation of a talk-show host, flitting from one subject to another, promising to return, telling the panel he was "sensitive to the time," although they gave him all he wanted. His problem, according to Bennett, is that his memory -- about what he got from Keating and how soon after he had done something for Keating -- has failed.

DeConcini was the most energized, the most substantive about his dealings with Keating. His body English was impressive too. He pushed up his sleeves when he told of doing community work in Phoenix. He told proudly of standing up to Keating, who had many chores for his senatorial backers.

He complained that Bennett had treated his fellow Arizonan, McCain, better than Bennett treated him. Later, he was asked if he thought this was political -- McCain was the only Republican of the five, and Bennett's brother, William, is about to be made chairman of the Republican National Committee.

"I hope not," said DeConcini piously.