A filibuster against a bill that would end contested elections of circuit court judges, begun Wednesday, continued early today in the Maryland Senate, with both sides declaring that debate will continue through the weekend.

A first attempt to shut off debate was easily defeated late last night, with 20 senators voting for cloture -- which requires 32 votes -- and 24 voting against.

Speeches droned on uninterrupted starting at midmorning yesterday after an overnight recess.

Because their usual committee meetings were canceled, lawmakers drifted out of the chamber for naps or newspaper reading in the Senate lounge, then drifted back in for brief appearances.

Lunch breaks were scheduled around expected appearances of favorite speakers.

"I'm going back. I hear state Sen. Clarence Mitchell's on at 2," said Sen. Frank J. Komenda (D-Prince George's), finishing lunch at the Maryland Inn.

"I hear he's going to read from 'The Brethren' a book by Washington Post reporters about the Supreme Court . I haven't read it so I hope he starts at the beginning."

Supporters of the bill, led by Montgomery state Sen. Margaret C. Schweinhaut and Prince George's Sen. Thomas V. Mike Miller Jr., both Democrats, say the change is necessary to improve the quality of circuit court judges and to protect them from the compromises inherent in political life.

Opponents, a politically diverse coalition led by Mitchell (D-Baltimore), argued that the current method provides accountability and allows minorities access to an elite institution.

Some white conservatives also agreed to help with the filibuster in exchange for help from blacks in an expected filibuster later this session over abortion.

Partly as a result of that support, leaders of the filibuster over judges' election said they had enough votes to prolong debate, though proponents of the bill said they had enough votes to pass the bill.

Because the measure is a constitutional amendment that would have to go to voters for approval, 29 votes are needed for passage.

Despite the occasional levity surrounding the filibuster, both sides were digging in for a long stay. Senate President Melvin A. Steinberg (D-Baltimore County) was counting heads. He said he would keep the Senate in session until 3 or 4 in the morning.

"The bill is difficult to amend. The question is elections or nonelections," he said. He said he expected to schedule several votes before a compromise can be arranged.

One compromise being floated by Republicans would still require contested elections but not until the election following the next scheduled election, so incumbent judges would have about three years on the bench before facing challengers.

A narrower bill was introduced last year but died in a House committee. This year's bill would require circuit court and district court judges to run on their records every 10 years but would remove the challenge of an opponent.

It also would require establishment of a judicial nominating commission whose members would be selected with Senate approval.

Such a commision now exists under executive order.