Originally Published: 10 APR 23 08:01 ET

Updated: 10 APR 23 09:01 ET

By Tierney Sneed and Lauren Fox, CNN

(CNN) -- The remarkable pace with which President Joe Biden has sought to remake the federal bench has been put into jeopardy by dual threats: Democratic Senate absences and a Senate rule that gives Republicans the ability to veto district court nominees for courts in their home states.

It's a combination that has Democrats increasingly concerned about the fate of future nominees at a time when the party had hoped to counteract years judiciary transformation under President Donald Trump.

The latest blow came last week when Biden's choice to fill a district court vacancy in Mississippi became the second nominee to be blockaded by the Senate rule, known as the blue slip tradition.

Mississippi GOP Sen. Cindy Hyde-Smith announced Tuesday that she would not return her "blue slip" for nominee Scott Colom, effectively sinking his nomination if Democrats choose to continue honoring the rule. The White House has said it is not backing away from its selection of Colom, currently the district attorney for the 16th Judicial District of Mississippi.

But even if Democrats wanted to push forward, the absence of California Sen. Dianne Feinstein, away from Senate for several weeks with a case of shingles, stands in the way. Without Feinstein on the panel, the partisan breakdown is 10-10.

No date has been given for the 89-year-old Feinstein to come back to Washington.

Senate Judiciary Committee Chairman Dick Durbin acknowledged to CNN that Feinstein's absence has slowed down their push to confirm nominees.

"I can't consider nominees in these circumstances because a tie vote is a losing vote in committee," Durbin said.

Asked if her absence has longer ramifications on the Democrats' ability to confirm nominees, the Senate chairman said "yes, of course it does," pointing to the long process of getting nominees scheduled for votes during precious floor time.

"We still have some nominees left on the calendar that we can work on ... But we have more in the wings that we would like to process through the committee," Durbin said.

Another Democrat who has not been present recently, Pennsylvania Sen. John Fetterman -- who is not a member of the Judiciary Committee but whose absence is complicating floor votes on nominees -- is slated to return on the week of April 17.

Biden closed out the first years of his presidency having put 97 judges, including Supreme Court Justice Ketanji Brown Jackson, on the federal bench and the Senate has since confirmed 22 more this year.

While the president likely won't match Trump's successes reshaping the US Supreme Court, his administration has focused on the lower courts. During the Trump years, Senate Republicans confirmed 229 judges, including three justices. The Biden administration has stressed not just the quantity of judges confirmed but also how Biden has sought to bring more professional and demographic diversity to the courts.

For Democrats, maintaining -- and growing -- their control of the Senate in last year's midterms has made that goal possible. But the new Congress has presented fresh roadblocks in the form of absences, blue slip issues and even skepticism from Democrats about a nominee championed by two members of their own caucus.

Ongoing debate over 'blue slips'

Even before Hyde-Smith announced her opposition to Colom, court watchers on the left were pressuring Senate Democrats to abandon the blue slip tradition. The rule has not been respected consistently through the modern history of the Senate, and Republicans nixed the requirement for US circuit court vacancies under Trump. Democrats, now in control, have refused to bring it back for appellate nominees, but Durbin has said he'd like to keep it in place for district courts.

Durbin didn't waver on that position when Sen. Ron Johnson flip-flopped last year on his support of a district court nominee in his home state, state Judge William Pocan, effectively torpedoing Pocan's nomination. A number of other district court vacancies in red states have been filled, with Republicans supporting Biden nominees, including a district court judge for an Indiana vacancy confirmed last month. A Biden nominee for a Louisiana district court has the support of its Republican Senate delegation, Sens. John Kennedy and Bill Cassidy confirmed to CNN.

Durbin's office blasted Hyde-Smith's opposition to Colom in a statement that did not indicate whether he was rethinking the blue slip rule. "In the coming days, he'll be assessing and will respond more fully," said his spokesperson Emily Hampsten.

White House press secretary Karine Jean-Pierre called Colom "deeply qualified" and referenced the support he's received as a district attorney from his constituents, who elected him in 2016 and reelected 2019.

"Sen. Hyde-Smith is preventing the people of Mississippi from having a judge in place in a timely fashion to uphold the rule of law for her state," Jean-Pierre said, declining to weigh in directly on whether the blue slip tradition should be done away with.

"I'll leave it to Congress ... to figure that piece out," Jean-Pierre said.

But as the Biden judicial push digs deeper into states where one or both of the senators are Republican, the blue slip debate will be harder to avoid.

"It was designed for senators to touch base with their local bar and judges and others because they have their ear to the ground and they are qualified to do a personal gut check, but to simply say I will not return a blue slip on someone because of x or y views is deeply abhorrent to the spirit of the blue slip process," Sen. Richard Blumenthal, a Democrat who sits on the Judiciary Committee, told CNN after Hyde-Smith announced her opposition to Colom.

Another fight may be brewing. Going into the current congressional recess, neither of Kansas' Republican senators had committed to supporting a Biden nominee for a judicial nominee for that state's district court.

Sen. Jerry Moran told CNN that he was in "conversation with the White House about judges," and Sen. Roger Marshall said he was waiting a rating from the American Bar Association on the nominee, Jabari Wamble. (Wamble did not received an ABA rating when he previously was put forward for an appellate opening last Congress, for which he was not confirmed; a spokesperson for the ABA told CNN that it does not comment about ongoing judicial reviews.)

Blue slip skeptics say that the practice is preventing Biden from even choosing nominees if the White House cannot reach a deal with Republican home states senators on someone they'll support.

"If it's a blue slip problem and the Republicans aren't turning in their blue slips and they're being obstructionist, then we need to think about changing the rules, said Democratic Sen. Mazie Hirono of Hawaii.

Republicans counter that they're not to blame for any standoff, pointing the finger at the White House for what they say is a failure to engage with senators on potential nominees.

"We're not the impediment, it's the White House," said Texas GOP Sen. John Cornyn, whose state has four district court vacancies in addition to an open seat on the 5th US Circuit Court of Appeals. "We're standing ready to help in any way we can, but they are so slow."

Democrats posing issues

Since Feinstein's absence was announced, the committee has only approved one nominee, judge Matthew Brookman, the GOP-supported appointee for the Indiana district court seat.

Ten nominees for Article III judgeships have been eligible since mid-March for a final committee vote that, if successful, would advance them to the Senate floor. Another two nominees had their committee hearings on March 22.

More than a dozen nominees are out of committee but await a vote on the floor, where both Fetterman and Republican Minority Leader Mitch McConnell are expected to return later this month after their health-related leaves.

Absences are not the only Democratic-related trouble spot Biden is facing on judicial nominees.

His choice for the 1st US Circuit Court of Appeals -- former New Hampshire Attorney General Michael Delaney -- has run into skepticism from Democrats because of how he approached representing an elite private school in a sexual assault lawsuit. Not every Democrat on the committee has committed to supporting him, with Hirono telling CNN earlier this month she was still undecided last week.

Delaney is among the nominees whose committee vote has been delayed while Feinstein has been absent from the Senate, but it is not clear that even if she returned the votes would be there to advance him.