President Barack Obama called Vice President Joe Biden "a lion of American history" when he surprised his close friend and deputy with a warm tribute and gave him the Presidential Medal of Freedom with Distinction, the highest U.S. civilian honor and one that has been bestowed only three times before.
The award, a surprise to Biden, was testament to the unusually close friendship between the two men, and to Biden's 44 years of public service — "making him one of the most consequential vice presidents in American history," according to the official citation.
Biden represented the state of Delaware for 36 years before becoming Obama's vice president in 2009.
In U.S. politics, the role of a vice president varies from one administration to another. Obama has relied on Biden and consulted with him more often than almost any other president, according to White House officials and veteran observers of the American political process.
FILE - President Barack Obama presents Vice President Joe Biden with the Presidential Medal of Freedom during a ceremony in the State Dining Room of the White House in Washington, Jan. 12, 2017.
In his effusive remarks Jan. 12, Obama said Biden is "the best vice president we have ever seen," and spoke of his memorable qualities of generosity and friendship.
"That is why my family is proud to call ourselves honorary Bidens," the president said, his voice cracking with emotion. As the Irish poet William Butler Yeats wrote, Obama said, "'Think where man's glory begins and ends, and say my glory was I had such friends.'"
Biden was in tears when he learned of the award. A presidential medal "with distinction" has only been awarded three times in the past — to Pope John Paul II, President Ronald Reagan and General Colin Powell.
FILE - President Barack Obama, right, honors Vice President Joe Biden, left, during a ceremony in the State Dining Room of the White House in Washington, Jan. 12, 2017.
Under the U.S. Constitution, the vice president's main official duty is to cast a vote on any issue in which the Senate is divided at 50 votes apiece; the president's deputy also serves as acting head of state in case the serving president is incapacitated and, of course, is first in the line of succession should the president die in office.
American vice presidents also preside over a joint session of Congress after each quadrennial election, to certify the vote of the Electoral College that formally decides on a president's election.
In some administrations, vice presidents have had a more distant relationship with the occupant of the White House.
Vice President John Nance Garner, who served under President Franklin D. Roosevelt from 1933-41, is frequently quoted as having said the vice presidency is "not worth a bucket of warm spit." (Actually, historians assert that he used a different word than "spit.")
In a review several years ago of "the vice presidents that history forgot," the Smithsonian Institution said the vice presidency in the past was "a rogues' gallery of mediocrities [and] criminals."
Garner had been Roosevelt's main opposition before the election of 1932, and he was only added to the Democratic ticket that year in a deal to ensure he would drop out of the party's internal presidential campaign. Garner broke with Roosevelt in 1937 over a controversial issue at the time — the president's bid to enlarge the Supreme Court — and openly campaigned against the measure, which was defeated.
FILE - Vice President Joe Biden takes the oath of office during the 57th Presidential Inauguration official swearing-in ceremony at the Naval Observatory in Washington, Jan. 20, 2013.
Biden, who is 74 years old, evokes a much warmer reaction from almost anyone who has known him, whether or not they were political allies.
Renee Van Vechten, professor of political science the University of Redlands in California, says the length of Biden's time in public service is memorable.
"He venerates public service and that's an honorable thing to do," she said. "It feels like a rarity among public servants today."
Furthermore, the professor notes, Biden "will also be known for that wink," and his public persona as a good-natured, fun-loving guy — a man known to his fans as "Uncle Joe."
At Thursday's White House ceremony, Obama recalled: "As one of his longtime colleagues in the Senate, who happened to be a Republican, once said, ‘If you can't admire Joe Biden as a person, you got a problem. He's as good a man as God ever created.'"
Biden, a middle-class lawyer from Scranton, Pennsylvania, won his first run for a Delaware seat in the Senate at age 29, turning 30 — the minimum age for a senator — just a few weeks before taking office in January 1973.
He initially became known for personal tragedy. Before he took office, Biden's wife and 13-month-old daughter were killed in a car accident, leaving the rookie U.S. senator with two young sons. Biden began traveling between Wilmington and Washington daily — usually by train, a 90-minute trip each way — to be sure he could see his sons before bedtime, and to maintain a semblance of normal home life.
The main railway station in Delaware's capital was renamed to honor Biden in 2011 to pay tribute to his marathon travels and devotion to his family — 7,000 trips back and forth over three and a half decades.
Biden was a single father for five years, then married educator Jill Jacobs, with whom he has a daughter, Ashley.
FILE - Vice President Joe Biden, left, and Jill Biden speak in celebration of World AIDS Day at Carnegie Hall in New York, Dec. 1, 2015.
In the Senate, Biden concentrated on issues such as consumer protection, environmentalism and government accountability. He later took on arms control issues and served as head of the Senate Judiciary Committee.
Biden came under criticism for the way he handled the Supreme Court confirmation hearing of Clarence Thomas in 1987, when former employee Anita Hill accused Thomas of sexual harassment.
Biden was accused by women's rights advocates and legal activists of suppressing Hill's testimony and not allowing other witnesses to testify on the same matter. Thomas was confirmed.
Biden later became an advocate for women's issues, including publicly opposing the Roman Catholic Church's stance on abortion and working to prevent violence against women.
Biden's first try at the presidency, in 1987, ended after allegations that he had plagiarized a speech made by a British politician. There were more revelations of possible plagiarism in other speeches, and Biden dropped out of the race in September of that year.
The vice presidency
Biden's position as a moderate Democrat who could work with Republicans, as well as a second, unsuccessful run for the presidential nomination in 2008, played into his selection to be vice president to Obama, a much younger man, who was to become the nation's first African-American president.
Their eight-year partnership soon turned into a deep friendship, as the two men met regularly for lunches where they discussed both policy issues and personal concerns.
FILE - President Barack Obama pauses while delivering the eulogy in honor of former Delaware Attorney General Beau Biden at St. Anthony of Padua Church in Wilmington, Delaware, June 6, 2015.
The depth of their friendship was apparent after the 2015 death of Biden's 46-year-old son, Beau, who suffered brain cancer. Obama gave the eulogy at the funeral.
Biden's tendency to speak frankly and off-the-cuff has made some headlines over the years.
After the 2010 passage of the health care bill known as Obamacare, Biden was caught on a live microphone at the Capitol congratulating Obama and telling him "this is a big [expletive] deal." The video went viral, and Obama referenced the matter recently, recounting the vice president's career in public service: "It is, as Joe once said, a big deal. It is."
During a television interview in 2012, Biden stated he was "absolutely comfortable" with gay marriage, before the president himself had clarified his position in support of the issue.
Biden's tendency to speak out of turn made him the perfect comic foil to the urbane Obama. Late-night television shows cast him as the class clown; The Onion satirical website developed a series about Biden called "The President of Vice."
After the election of Republican Donald Trump in November 2016, internet memes began to circulate, featuring Biden plotting mischief while Obama acts as the voice of reason.
A sample: A photograph of Obama on the telephone in the Oval Office, with an amused-looking Biden in the background, is captioned: "I know Joe called and ordered 500 pizzas to be delivered on January 21st, but I need you to cancel that order."
Internet jokesters will miss him
Meanwhile, as Obama and Biden prepare to leave office, Biden's approval ratings are higher than they have been in years, and internet wags are waxing sentimental about the departure of Uncle Joe, internet goofball.
FILE - U.S. President Barack Obama, right, opens his wallet to buy lunch for himself and Vice President Joe Biden at a sandwich shop near the White House in Washington, D.C., Oct. 4, 2013.
But experts say Biden's real legacy will be his close relationship with Obama and his "regular guy" persona.
David O'Connell, professor of political science at Dickinson College in Carlisle, Pennsylvania, says Biden's real distinction as a vice president was in his close relationship with the president, both as adviser and personal friend.
Biden "was asked to be a sounding board for Obama, someone who could use his more extensive national experience in order to help Obama make better decisions," O'Connell said. "It is clear he played this role well. Their friendship is real and genuine."
‘Never say never'
Natalie Davis, professor of political science at Birmingham-Southern College in Alabama, notes that Biden has a history of working well with both parties and relating to the middle class.
"In the south, we would call him a good ole boy, because he represented real people with real problems, a real working-class guy who never did forget where he came from," she said. "I don't think that was a media-constructed image. I think that's Joe."
While he leaves the vice presidency at age 74, Biden has not said whether he is done with politics. When asked about a possible presidential run in 2020, Biden told reporters in December that he is "not committing not to run" despite the fact that he would be 77 then, older than any previous presidential candidate. Talk show host Stephen Colbert asked him directly about a possible presidential run, to which Biden replied, "Never say never."