The Senate judiciary committee on Monday neared a vote on the historic nomination of Ketanji Brown Jackson, poised to be the first Black woman confirmed to the supreme court.

Following days of interrogation and debate over Jackson’s qualifications, the committee vote was expected to be evenly split, 11-11. That would force Democrats to “discharge” the nomination, delaying but not denying confirmation.

Before the vote could take place, the committee adjourned to await the arrival of its 22nd member, the California Democrat Alex Padilla, whose flight to Washington was delayed.

A vote to discharge Jackson’s nomination was expected as early as Monday evening. That would set up hours of additional debate on the Senate floor.

Democrats and the White House hope to confirm Jackson to the lifetime position on the court before Congress recesses for the Easter holiday on Friday. The 51-year-old was confirmed by the Senate to the US court of appeals for the DC circuit last year with the support of three Republicans.

Only one of those Republicans, Susan Collins of Maine, has committed to voting for her again.

Lindsey Graham of South Carolina has said he will not support Jackson’s nomination to the supreme court​​, calling her an “activist to the core”, outside the judicial mainstream.

Lisa Murkowski of Alaska has not said how she intends to vote, but is seen as one of only two more Republicans, along with Mitt Romney of Utah, who might support Jackson.

If confirmed, Jackson will replace the retiring liberal justice Stephen Breyer, for whom she clerked, and would make history as the first Black woman and only the sixth woman to sit on the court in more than 200 years. Her confirmation would, however, do nothing to change the ideological balance of a court on which conservatives outnumber liberals 6-3.

In his opening remarks on Monday, Dick Durbin of Illinois, the committee’s Democratic chair, praised Jackson’s “impeccable qualifications” and said her experience as a public defender would bring a “missing perspective to the court”.

“This committee’s action today in nothing less than making history,” Durbin said. “I’m honored to be a part of it. I will strongly and proudly support Judge Jackson’s nomination.”

Durbin also lamented Republican hostility toward Jackson, accusing senators of leveraging “vile” and “discredited” attacks on her record and character.

“She stayed calm and collected. She showed dignity, grace and poise,” Durbin said. “It is unfortunate that our hearing came to that, but if there is one positive to take away from these attacks, it is that the nation got to see the temperament of a good, strong person truly ready to serve on the highest court in the land.”

Many Republicans used the hearing on Monday to rehash their attacks on Jackson, accusing her of handing down lenient sentences to child sex crime offenders when she was a federal trial court judge, a claim independent factcheckers have said is baseless and lacks context.

During her hearings, Jackson forcefully defended her record, telling senators these were among the most traumatic and haunting cases she dealt with and that she did her “duty to hold the defendants accountable”.

Republicans also sought to portray Jackson as “soft on crime”, a line of attack dismissed outright by the American Bar Association, which testified that she was strongly qualified for the position.

Republicans on the committee appear uniformly opposed to Jackson’s nomination, starting with the ranking member, Chuck Grassley of Iowa, who announced he would not vote to confirm Jackson because “she and I have fundamental, different views on the role of judges and the role that they should play in our system of government”.

On Monday, Graham again used his time to decry Democrats’ treatment of nominees named by Republican presidents.

“If we were in charge, she would not have been before this committee,” Graham said.

His point was that Republican control of the Senate would have forced Democrats to put forward a more “moderate” – in his view – nominee. But Democrats saw the comment as a plain-spoken acknowledgment of Republicans’ hardball tactics when it comes to the supreme court, after the GOP refused to let Barack Obama fill a vacancy in 2016 – an act without precedent.

Cory Booker, a New Jersey Democrat, compared proceedings on Jackson’s nomination to Festivus, the holiday celebrated on the TV series, Seinfeld.

“There’s been a lot of airing of grievances,” Booker said, adding: “I’ve heard things that are just ridiculous.”

During more than 30 hours of hearings last month, Jackson pledged to be an independent justice who would decide cases from a “neutral position”. She defended her record while reflecting on her personal story as the daughter of public school teachers in the segregated south.

As the 22-member panel convened on Monday, Joe Biden said Jackson would “bring extraordinary qualifications, deep experience and intellect, and a rigorous judicial record to the supreme court.

“She deserves to be confirmed as the next justice.”