Sen. Tim Kaine (D-Va.), the 2016 vice presidential nominee, is endorsing former vice president Joe Biden for the Democratic presidential nomination, hoping to give him a boost before Saturday’s South Carolina primary and Virginia’s primary on Super Tuesday.

“It is sad to have a President who no one holds up as a role model for America’s kids. By contrast, Joe Biden has exemplary heart, character, and experience,” Kaine, a two-term senator, said in a statement provided to The Washington Post.

Kaine likened Biden to the 33rd president of the United States, Harry S. Truman, whom Kaine has described as his political hero — next to his father-in-law, former Virginia governor Linwood Holton — because of Truman’s compassion for everyday people.

“He reminds me of Harry S. Truman, an outwardly ordinary man whose work ethic, faith in the goodness of everyday Americans, and love of country made him a great President,” Kaine said in the statement. “I am proud to vote for Joe Biden.”

The endorsement comes at a critical time for Biden, who has struggled in early nominating contests and considers South Carolina, where he is leading in polls, a crucial firewall. A Wason Center poll of likely Democratic voters in Virginia released Friday found Biden with a modest lead in that state as well, with Sen. Bernie Sanders (Vt.) and former New York Mayor Mike Bloomberg in second and third place, respectively.

Kaine is also close to presidential hopeful Sen. Amy Klobuchar (D-Minn.), with whom he has teamed up on legislation. But she has struggled to find momentum since her third-place finish in the New Hampshire primary. Klobuchar, Sen. Elizabeth Warren (Mass.), former South Bend, Ind. mayor Pete Buttigieg and financier Tom Steyer were all in single digits in the Wason Center poll.

“Democrats have many good public servants and admirable people running for President,” Kaine said in the statement.

In 2007, Kaine was governor of Virginia. He became the first sitting governor outside Barack Obama’s home state of Illinois to endorse Obama’s first campaign for president; he and was on Obama’s final list of possible running mates, but Obama picked Biden.

“Barack Obama wisely chose Joe as his partner in the White House,” Kaine said Friday. “And for eight years, Vice President Biden worked hand-in-hand with President Obama to rescue the American economy from catastrophe, expand health care to millions of people, revive creative diplomacy to keep Americans safe, tackle global challenges like climate change, and appoint high-quality people across the executive and judicial branches of our government. As a Senator, I saw first-hand Joe’s role in these accomplishments.”

In Virginia, Democratic Reps. A. Donald McEachin and Elaine Luria have also endorsed Biden.

Kaine, 62, was a civil rights lawyer in his adopted hometown of Richmond before entering politics. He was elected to the Senate in 2012, and serves on the Foreign Relations and Armed Services committees.

He has an approval rating of 55 percent among Virginians, a February 2019 Quinnipiac University poll found.

Kaine has decried the polarization in national politics today, and says he would like to fashion his Senate service after retired senator John Warner, a Republican who spent 30 years in office representing the state of Virginia.

“America is afflicted by a President who delights in division, cruelty, lies, chaos, and self-congratulation,” Kaine said Friday. “We are better than that, and Americans deserve better in the Oval Office.”

Scott Clement contributed to this report.

This is a developing story. It will be updated.