Not the first time a sitting president has dropped out of reelection race

President Joe Biden’s decision to withdraw makes him the first sitting commander in chief to withdraw from the race since Lyndon B. Johnson in 1968 — a move which shook the Democratic Party and historians say helped hand the White House to Republican Richard Nixon.

Johnson's decision on March 31, 1968, took the nation by surprise. But it came amid a souring approval rating over his handling of the Vietnam War, despite several policy wins like the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the creation of Medicare and Medicaid.

The contested race ultimately became a three-way between Robert F. Kennedy, Vice President Hubert Humphrey and U.S. Senator Eugene McCarthy. Kennedy — a popular antiwar candidate — was assassinated in June that year.

Johnson was tapped as vice president following the 1960 election and went on to serve as president following the assassination of President John F. Kennedy in 1963. He was the party frontrunner before he opted to step down from the race, roughly seven months before the general election.

"I do not believe that I should devote an hour or a day of my time to any personal partisan causes or to any duties other than the awesome duties of this office — the presidency of your country," Johnson said in his televised remarks. "Accordingly, I shall not seek, and I will not accept, the nomination of my party for another term as your president."

Humphrey ultimately went on to win the Democratic nomination in Chicago that year. But the Democratic National Convention in Chicago that August was ultimately marred by civil rights and antiwar protests both physically at the convention and around the globe, coming on the heels of the assassination of civil rights leader Martin Luther King Jr.

The division in the Democratic party “allowed Nixon to take on a divided party to appeal to a sense of law and order” and win the election in 1968, said Micah Rasmussen, director of the Rebovich Institute for New Jersey Politics at Rider University in Lawrenceville.

Years later in 1980, the Democratic Party once again found itself divided — though not as fiercely — when U.S. Senator Ted Kennedy tried to take on sitting incumbent Jimmy Carter.

Kennedy issued his famous "The Dream Shall Never Die" speech in Madison Square Garden during the convention that year, in which he rebuffed Carter's administration and what he viewed as more moderate stances by the incumbent.

Joe Biden: Read President's full statement as he drops out of 2024 presidential race

“It was disastrous,” Rasmussen said. “Carter was weakened sufficiently — he was rocked by world events.”

Republican Ronald Reagan was ultimately victorious in that year’s elections.

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One-term presidents who did not seek reelection

Rutherford B. Hayes opted not to seek a second term in 1880, as did James Buchanan and James Polk.

Calvin Coolidge took the mantle of the presidency after the death of Warren Hardin in 1923 and won a four-year term the next year, though he opted not to run for president four years later.

Harry S. Truman, who started out as vice president under President Franklin D. Roosevelt and ascended to the role upon FDR's death, also dropped out of the race in 1952 after low approval ratings.

The presidential debate behind Joe Biden's loss of support

Sunday's decision marks an extraordinary turn for Biden, who for three weeks remained defiant in the face of growing calls from Democratic lawmakers that he withdraw after a disastrous June 27 debate with Trump raised scrutiny over the president's mental fitness.

More: New Jersey reacts to President Biden bowing out of presidential race

Biden threw his support behind Vice President Kamala Harris in a social media post on Sunday to take on Republican nominee and former President Donald Trump in November.

The Democratic party will nominate a candidate to go up against Trump at its national convention in August.

“The Democrats really have to get their ducks in a line very quickly,” said Rasmussen of Rider University. “If they can’t - history will tell us they’re going to struggle.”

"The appeal here would be that Trump would be able to offer a credible alternative to the disorder of the Democrats," he continued.

Though Ross Baker, a professor of American politics at Rutgers University, said that should be easy for the Democratic party.

“They’ve been living in this period — week after week — of uncertainty after the debate,” he said in a phone interview. “Everybody was very badly shaken by that.”

Baker said Sunday's news “is like nectar in the desert for Democrats.”

This article contains information from USA Today

Daniel Munoz covers business, consumer affairs, labor and the economy for NorthJersey.com and The Record.

Email: munozd@northjersey.com; Twitter:@danielmunoz100 and Facebook

This article originally appeared on NorthJersey.com: Joe Biden not the first president to drop out of reelection race