Sen. Frank Lautenberg (D-N.J.), 89, died Monday morning after serving in Congress for more than 30 years.
According to his office, Lautenberg died of viral pneumonia. He was the oldest member of the Senate and had recently missed several weeks of votes because of illness.
The loss comes at an inopportune time for Democrats, shortly before the biggest legislative initiative of the session, comprehensive immigration reform, reaches the floor this month.
Democrats, however, have been operating for weeks without Lautenberg, who missed dozens of votes because of illness. He made a dramatic appearance on the Senate floor in April to vote for expanded background checks for gun sales. Prior to that, he had not cast a vote since late February, and he has not been seen on the Senate floor since.
Senate GOP aides expect New Jersey Gov. Chris Christie (R) to appoint a Republican, and the possibilities include Lt. Gov. Kim Guadagno, state Sen. Tom Kean Jr., who ran against Sen. Robert Menendez (D-N.J.) in 2006 and attorney Bill Palatucci, a longtime friend and adviser to Christie.
According to New Jersey election law, Christie may appoint a replacement to temporarily fill Lautenberg's seat until a special election occurs to elect someone to serve out the remainder of Lautenberg's term.
Christie may set the date of the special election. It's unclear whether he'll choose to schedule it on the same day as the gubernatorial and state legislative elections on Nov. 5.
Setting the special on the same date as the upcoming gubernatorial election could give a boost to a Republican candidate from Christie's coattails, as he's running far ahead of the Democratic candidate for governor and is expected to easily defeat her.
Lautenberg had announced earlier this year that he was not going to seek reelection in 2014. He served on the Senate Appropriations Committee as well as the Commerce, Science and Transportation, and Environment and Public Works committees.
Lautenberg was the last World War II veteran serving in the U.S. Senate and held the record for the number of votes cast by a New Jersey Senator with more than 9,000. Some of his signature legislative issues were gun control, G.I. benefits and chemical safety.
In a statement, President Obama said Lautenberg had "improved the lives of countless Americans with his commitment to our nation’s health and safety, from improving our public transportation to protecting citizens from gun violence to ensuring that members of our military and their families get the care they deserve."
Senate colleagues from both sides of the aisle praised Lautenberg’s service and collegiality.
“From his work to prevent gun violence, to ending smoking on planes, to his commitment to protect families from dangerous chemicals, Frank Lautenberg was a champion for the underserved and underrepresented," Sen. Patty Murray (D-Wash.) said Monday. “Frank was a passionate public servant who was not afraid to fight and vote for what he believed in. He loved the Senate."
Senate GOP Leader Mitch McConnell said Lautenberg's death was a blow to the body.
“The Senate’s last remaining World War II veteran, Frank was a patriot whose success in business and politics made him a great American success story and a standout, even within the fabled Greatest Generation," he said.
“It was with great sadness I learned of Senator Lautenberg’s passing,” said Sen. Lindsey Graham (R-S.C.). “He was a fine man who served his nation honorably in World War II. He was a true gentleman who will be missed by his family, friends and colleagues in the United States Senate.”
“One night early on in my time in the Senate, we were here very late voting, and Frank graciously invited me to dinner. It was the first time I got to see not ‘Senator Lautenberg,’ but ‘Frank,’ just hanging out, telling stories and jokes, and being an engaging, positive and just inspiring person,” recalled Sen. Chris Coons (D-Del.). “He will certainly be missed.”
“Whether it was his landmark drunk driving law, the 21st Century G.I. Bill, or the “Toxic Right to Know” law empowering the public to know what pollutants are being released into their neighborhood, he was a fighter for New Jersey’s working families and the causes he believed in,” added Menendez, who has worked with Lautenberg representing New Jersey in the Senate since 2006.
Lautenberg retired from the Senate in 2000, but ran again in 2002 after Sen. Bob Torricelli (D) withdrew from the race because of ethics violations.
This story was published at 9:52 a.m. and has been updated.
Alexander Bolton and Alexandra Jaffe contributed to this story.