The year was 1963. Biden, then a student at the University of Delaware, had come to Washington to visit friends when he decided to stop by the US Capitol. As Biden tells it, he parked his car in front of the Capitol and walked up the steps. A rare Saturday session had ended, and the Senate chamber was empty with the lights still on.

"There were no signs then," he recalled in his 2009 farewell address to the Senate, one prominent telling of this bit of Biden lore. "I just walked in."

Not quite understanding the feeling that overtook him, Biden bounded up to the dais and sat down in the presiding officer's chair.

"I was awestruck," he said. "Literally awestruck."

It wasn't long before the young Biden was noticed.

"A Capitol policeman picks me up and spins me around, and he said, 'What are you doing?' " Biden recounted as his colleagues laughed. "And after a few moments, he realized I was just a dumbstruck kid and didn't arrest me or anything."

Whether or not the story is true -- only Biden knows that -- it says something about the man, and in particular the central role the Senate has played throughout his life.

Just a decade after getting caught in that chair as a college student, Biden became one of the youngest people ever elected to the Senate. Over the next 45 years, a period stretching over more than half his life, the chamber of the US Senate served as the backdrop for all of Biden's triumphs and tragedies.

Now, as Biden attempts a third act in his political life, and reaches for what would be a crowning political achievement, the Senate has once again become the setting for a family tragedy of sorts.

Ever since President Donald Trump's lawyer Rudy Giuliani began publicly spreading unfounded allegations of corruption against them last year, Biden and his son Hunter have been in the sights of the President's political operation. While Trump's focus on Biden may reflect some inner fear that Biden could be the biggest threat to his reelection, it has also forced the former vice president to address uncomfortable questions while on the trail, as well as drawn public attention to Hunter Biden's embarrassing personal troubles.

As the trial moved to the Senate, Biden's name has echoed throughout the chamber again, as he and his son have been dragged into the proceedings and tagged by Republicans with allegations of corruption. There was even a push from some in the GOP to call Hunter Biden as a witness.

Trump and his allies have repeatedly made unfounded and false claims to allege that the Bidens acted corruptly in Ukraine.

Now that the trial is winding down, there is a real question about whether Trump's gambit to drag down a top opponent was worth it. For Trump, who will likely be acquitted , he can run against Democrats in the fall for leading a "witch hunt" against him. Biden, on other hand, has struggled to absorb the attacks and respond effectively.

For an institution that was the backdrop of so much of Biden's ups and downs, there's a certain irony that the Senate and its ongoing trial would be an obstacle to his bid for the White House.

"I think he's not surprised," said Ed Rendell, a former Pennsylvania governor and a longtime Biden friend, who said he had spoken to Biden a few days before the trial began. "I think he was a little discouraged."

A young senator

Within months of his election at age 29, before he had even been sworn in, Biden was widowed when his wife and infant daughter died in a car crash. His two sons grew up among his Senate colleagues, often accompanying him to the Senate floor. Biden forged his political career in the halls of the Senate, carving out a role for himself as a deal-making moderate, a law-and-order liberal and powerful committee chair.

A few months later, he nearly died from two brain aneurysms while he was chairman of the Judiciary Committee. Biden launched two unsuccessful bids for the White House from the Senate, the first in 1987. Beset by accusations of plagiarism , he withdrew that September.A few months later, he nearly died from two brain aneurysms while he was chairman of the Judiciary Committee.

Twenty years on, when Biden finally left for his second act as vice president under Barack Obama, he still presided over the Senate, remaining a fixture on Capitol Hill throughout his two terms.

"The United States Senate has been my life," Biden said in his 2009 address. "Except for the title 'father,' there is no title, including 'vice president,' that I am more proud to wear than that of United States senator."

Sen. Tom Carper, a Delaware Democrat who served with Biden and considers him a close friend for more than 40 years, acknowledged the difficulties the trial is causing for Biden, personally and politically.

"In our business you have to have a pretty thick skin, but this is probably about as tough as it gets," Carper told reporters in the Capitol this week.

His allies say they don't doubt Biden is handling the centrality of his family in the impeachment proceedings well.

"I know him very well, so I know the character, I know the mettle that's in the spine, and that makes a difference," said Democratic Sen. Dianne Feinstein of California, who added that she has not been in touch with Biden since the trial began.

Democratic Sen. Chris Coons of Delaware, who now occupies Biden's seat, downplayed the idea that the former vice president's relationship with the Senate might be damaged by his treatment in the trial.

"He has decades of positive memories to draw upon, of moments of genuine progress, of great compromises, of meaningful bipartisanship," Coons told CNN.

A different kind of Senate

US Vice President Joe Biden speaks during the dedication of the Edward M. Kennedy Institute for the United States Senate in 2015.

Today's Senate is different from the one Biden left in 2009. Just a third of the current membership served alongside him. Old institutionalists, such as the former Republican senator from Maine William Cohen, complain that the rough-and-tumble partisanship of the House of Representatives has now infected the upper chamber. (Nearly half of the current 100 senators are former House members.)

"There was a sense that, in the Senate, it was a club. You had to get along because you've got to live with these people," said Cohen, who went on to serve as secretary of defense under President Bill Clinton. "That's gone now. It's like the House."

But for Republicans, even those who served alongside Biden, there's little recognition that some sort of collegiality should be extended to Biden in the midst of a heady, partisan impeachment saga.

Take Sen. Lindsey Graham, who in a 2015 interview with the Huffington Post became choked up when talking about his friendship with Biden and sharing the pain of the death of Biden's elder son, Beau, earlier that year.

"If you can't admire Joe Biden as a person, then it's probably you've got a problem," the South Carolina Republican said. "He is as good a man as God ever created."

But this week, as the debate over witnesses was just heating up, Graham insisted Republicans would need to call Hunter Biden to testify.

"I want to know is there a reasonable belief by the President that the Bidens are involved in corrupt behavior," Graham told reporters Monday.

Rendell, who is supporting his longtime friend in the Democratic primary, said Republicans like Graham know better about their former colleague's character.

"I think it's frustrating and a little bit heartbreaking to hear these Republicans say this stuff just to save their own skin," the former governor said.

There's also the added pain, Rendell said, of having Hunter Biden, who Joe Biden refers to as his "surviving son" and who faces a number of personal problems, at the center of the trial.

"To see what happened to your first son and see this happen to your second son, it's just awful," Rendell said.

Taking a punch

Biden speaks during a campaign town hall event at the Iowa Memorial Union Ballroom at the University of Iowa on January 27

While Biden's name is a fixture in the debates taking place on the Senate floor during the impeachment trial, he has remained hundreds of miles away. Recently, the 77-year-old has been campaigning in Iowa, trying to push his advantage before Monday's caucuses since three of his top rivals have been stuck at their Senate desks in Washington.

At stop after stop on his final bus tour through Iowa , Biden has argued that attacks from Trump and his allies have made him stronger and have demonstrated that he can take incoming fire if he's the Democratic nominee.

"As much as he's trying to destroy me and my family -- I hope I've demonstrated I can take a punch. And if I'm our nominee, he's going to understand what punches mean," Biden said in Cedar Falls on Monday.

He has told the reporters covering his campaign, "Keep asking me, 'You know, they just brought up your son Hunter, and they're doing this and they're doing that and the other thing.' "

"Well, guess what?" Biden said. "I don't hold grudges because presidents can't hold grudges. Presidents have to be fighters, but they also have to be healers. They have to be healers."