The most awesome power the law can give one man over another - the license of a judge to take life, deprive liberty and confiscate material wealth - was being discussed one day last week, almost out of public view, in a small conference room in the Capitol.

Sen. Joseph R. Biden (D-Del.) was submitting to the Judiciary Committee an amendment to the proposed revision of the U.S. criminal code. He was in the midst of a monologue on the need to allow time off for good behavior, explaining that his amendment proposed a "two-for-one" provision to assure well-behaved inmates early release.

"In other words, for every day of good behavior in prison - excuse me, I am being corrected here," Biden said, as members of his staff thrust a copy of his own amendment at him.

Then, seemingly confused and stumbling somewhat over his words, Biden attempted to digest and explain what his staff had prepared. Finally, he started his colleagues and the audience with a frank admission:

"Obviously, I don't know what the hell I'm talking about. I thought I had a two-for-one provision there. The staff, in its wisdom, rewrote it, so I guess I did not want that after all."

Beside providing a laugh for the committee and spectators, Biden's confusion illustrated dramatically the difficulty that busy legistors have in grasping the complexity of a 360-page bill that rewrites 200 years of federal criminal laws.

It also illustrated how delicate is the compromise made between Sens. Edward M. Kennedy (D-Mass.), representing the liberals, and John L. McClellan (D-Ark.), representing the conservatives.

The deal actually was struck more than a year ago, when the late Sen. Phil Hart (D-Mich.) and former Sen. Roman Hruska (R-Neb.) joined Kennedy and McClellan in forming an extraordinary coalition of political opposites in hopes of salvaging something from the disastrous S1. That criminal code bill, under constant attacky by liberals for its hard-line position on civil liberties, languished and died in committee.

McClellan has been seriously ill, and conservatives took up his cause in his absence as a tribute to his perseverance: when Hart died, liberals on the committee felt they were carrying on his campaign to improve the code while excising S-1's "repressive" elements.

But now a flurry of amendments submitted by liberals has distressed supporters of the bill to the point that one key Senate aide involved in the drafting said last week, "We're near the end. We're down to the gut issues, and the question is, are the liberals on this committee going to commit suicide?"

Part of the problem, committee sources say, is indifference. Chairman Sen. James O. Eastland (D-Miss.) has had continual problems getting nine members together for a markup quorum.

Also troublesome, the bill's supporters say, is the problem of explaining to busy colleagues the details of an enormously complex bill.

But most of all, sources say, the bill is in trouble because of disorganization among liberals on the committee.

"The ACLU and other groups are lobbying the hell out of them. They've forgotten everything that has been delicately put together by Kennedy and McClellan. It is fair to say that if this bill goes down the drain, the liberals will have killed it, and they will have only themselves to blame," a Senate source complained bitterly in an interview.

Dramatic evidence of that came last week when Sen. Birch Bayh (D-Ind.), one of the liberal members, introduced an amendment decriminalizing possession of small amounts of marijuana.

It was adopted, and this so angered conservatives the committee that Sen. Orrin Hatch (R-Utah) said he will propose a substitute amendment to make possession of small quantities of marijuana a criminal infraction.

"More moves like Bayh's can mean disaster. This whole coalition is very delicate, and the liberals have got to get their act together and go along with what Kennedy and McClellan have put together. Or else, the whole thing could go down," said a source close to the committee.

Another markup session is planned for Monday, committee aides said, if McClellan can get a quorum together.