The Senate could confirm President Biden’s Supreme Court nominee without a single Republican vote, but Mr. Biden and Democrats would like to avoid that outcome if possible — and Judge Ketanji Brown Jackson has drawn some G.O.P. support in the past.
Even before Judge Jackson was chosen, the president and Senator Richard J. Durbin, Democrat of Illinois and chairman of the Judiciary Committee, began reaching out to Republicans they saw as potentially open to supporting a Biden nominee, including Senators Susan Collins of Maine and Mitt Romney of Utah.
Democrats say that bipartisan backing for the nominee helps build her credibility and that of the court. They also hope that some Republicans will welcome the opportunity to support the first Black woman to join the high court and be willing to put aside any ideological differences if they consider the nominee qualified for the job.
As long as all 50 Democrats back the nominee, support from at least one Republican would also avoid the spectacle of Vice President Kamala Harris having to break a tie to seat a new justice, which would be a first in Supreme Court confirmation history.
But chances for a significant bipartisan vote appeared minimal.
Ms. Collins, along with the Republican Senators Lisa Murkowski of Alaska and Lindsey Graham of South Carolina, were the only Republicans to vote for Judge Jackson when she was confirmed to the U.S. Court of Appeals for the District of Columbia Circuit last June.
While additional Republicans could still decide to back her for the Supreme Court, it would be unusual for a senator who opposed a nominee for a lower court to then support her for a higher judicial position.
And on Friday, Mr. Graham, who had pressed for Mr. Biden to choose Judge J. Michelle Childs of South Carolina for the vacancy, cast substantial doubt on his willingness to support Judge Jackson’s confirmation.
Senators Murkowski and Collins have both shown a willingness to support the judicial nominees of Democratic presidents, and Ms. Murkowski has new political incentive to do so. She is seeking re-election in Alaska under a new election system and could benefit from the support of independents and Democrats supportive of Mr. Biden’s choice.
Ms. Collins issued a statement on Friday in which she complimented Judge Jackson’s qualifications and suggested she was undecided about how to vote.
“Ketanji Brown Jackson is an experienced federal judge with impressive academic and legal credentials.” Ms. Collins said. “I will conduct a thorough vetting of Judge Jackson’s nomination and look forward to her public hearing before the Senate Judiciary Committee and to meeting with her in my office.”
In an attempt to nail down their backing, Democrats have told the senators they would provide requested materials and set up meetings with the nominee so they could have whatever they needed to reach a decision.
Taking a seat on the court without the support of any senator from across the aisle would not be a first. Justice Amy Coney Barrett was confirmed in October 2020 with no Democratic votes after her nomination by President Donald J. Trump.