Sen. Dianne Feinstein flew back to Washington on Tuesday, her spokesman said, after her extended absence due to the shingles virus threatened to derail Senate Democrats’ agenda.

The senator’s absence caused mounting heartburn for the Democratic majority, which has few votes to spare to confirm President Joe Biden’s Cabinet and judicial nominees, as well as potential legislation to avert a default on the national debt.

Sen. Dianne Feinstein, D-Calif., is returning to Washington after a more than two month absence, which led to calls from within her own party for the oldest member of Congress to resign. J. Scott Applewhite/Associated Press file

Senate Majority Leader Charles E. Schumer, D-N.Y., said in a statement that after talking with Feinstein several times in recent weeks, “it’s clear she’s back where she wants to be and ready to deliver for California.”

“I’m glad that my friend Dianne is back in the Senate and ready to roll up her sleeves and get to work,” he added.

The San Francisco Chronicle reported that Feinstein, who had been convalescing in the Bay Area since mid-February, boarded a charter private plane Tuesday to return to the Senate. Adam Russell, a spokesman for the Democratic senator, confirmed she arrived in the Washington area Tuesday evening but declined to comment further.

Feinstein, 89, has contended with questions about her health and ability to serve for several years, and her slow recovery from the shingles virus and related complications led some Democrats, including Rep. Ro Khanna, D-Calif., and Rep. Alexandria Ocasio-Cortez, D-N.Y., to call for her resignation.

On Tuesday, Khanna said he was glad to hear of Feinstein’s return, and he was “hopeful that she will be able to fulfill her duties.”

“The people of California deserve strong representation and a senator who can vote to advance President Biden’s judicial nominees and protect Americans’ fundamental rights. The three-month absence hurt our agenda, and time will tell on the future,” Khanna said.

Feinstein has missed nearly 80 votes this year, according to ProPublica – the most of any senator. Her absence has been keenly felt on the Senate Judiciary Committee, where, without Feinstein, Democrats needed at least one Republican vote to advance Biden’s nominations for federal judges.

As outcry grew about her absence, Feinstein asked for another Democrat to temporarily be appointed to the panel in her place. Republicans rejected that effort.

The blockade threatened to stymie Biden’s rapid clip of securing judicial confirmations, which Carl Tobias, a professor of law at the University of Richmond, called “the best-kept secret around.” He said Biden has been open in his goal of appointing judges that would offset the conservatives confirmed under former President Trump.

“He pledged he would counter that and he has,” Tobias said.

In a statement last week, Feinstein responded to critiques that she was causing a backlog for the Judiciary Committee and said she would be returning to Washington, without specifying a timeline.

Her Democratic colleagues in the Senate had mostly demurred on weighing in on what she should do, although there were some flashes of anxiety as the weeks progressed.

“I want to treat Dianne Feinstein fairly. I want to be sensitive to her family situation and her personal situation. And I don’t want to say that she’s going to be put under more pressure than others have been in the past,” Sen. Richard J. Durbin, D-Ill., said Sunday on CNN. “But the bottom line is, the business of the committee and of the Senate is affected by her absence.”

With Feinstein’s return to the Senate, Democrats will have an 11-10 edge on the Judiciary Committee, enabling Biden’s nominations to progress to the full Senate without needing a GOP vote. The committee is due to meet Thursday to consider nominations to the federal bench.

The cross-country trip Tuesday may also serve to dampen growing complaints about a lack of transparency from Feinstein’s office on details about her medical condition. Last week, her staff declined to give The Times a report or interview from her doctor.

Indivisible California, a progressive group, issued a letter calling on Feinstein to resign because of her absence. Representatives were invited to a Zoom call with Feinstein’s staff last week, which they said was devoid of specifics about her condition.

Patti Crane, a member of Indivisible’s South Bay L.A. chapter who participated in the call, said Feinstein’s trip back to Washington was a positive development.

“We’re just thrilled that she’s well enough to climb on that chartered plane and get to Washington,” Crane said. “It’s great that she’s been eating her Wheaties and is healthy and robust so she can keep fighting for Californians.”

Still, some progressives said they continue to have concerns about the senator’s health. Aimee Allison, founder and president of She the People, an advocacy group pushing for more women of color to hold elected office, called for “assurances that the senator will be able to fully represent our state and carry out the duties of her position.”

“Sen. Feinstein’s absence has made the work of ensuring the best for our state and country more difficult, and we hope that her return is one that we can count on. If not, it is time for us to have a necessary discussion about the future of the California Senate seat,” said Allison, who is backing Rep. Barbara Lee (D-Oakland) in next year’s race to succeed Feinstein. The senator is not seeking reelection.

Two of the Democrats vying for the Senate seat – Rep. Adam B. Schiff of Burbank and Rep. Katie Porter of Irvine – said they welcomed Feinstein’s return. (Lee could not be reached for comment). The sentiment was echoed by California’s junior senator, Alex Padilla, who said he knew Feinstein was “eager to return to continue our important work.”

The Senate contest, which began in earnest even before Feinstein announced in February she would not run again, had also been affected by the uncertainty over her health. The lengthy absence had set off fresh speculation about what would happen if Feinstein could not complete her final term and whom Gov. Gavin Newsom would appoint to fill her seat.

Newsom, who had committed to appointing a Black woman to the Senate if he had the opportunity, said Feinstein’s health troubles set off a deluge of questions about what he would do.

“Emails, calls, texts, people stopping me – I’m not kidding, this is one of the biggest topics here,” Newsom said in a television interview last week.

His office declined to comment on her return to Washington.