When Joe Biden takes the stage at the Democratic National Convention on Wednesday night, there is probably a part of him that still wonders, "What if?"
But his own White House dreams and reported rivalry with Hillary Clinton will have to be in the rearview mirror in order for him to deliver a home run endorsement, starting on stage and continuing through November.
"I had planned on running for president, and life intervened," the vice president told his local paper, the Delaware News Journal, last week. "I made the right decision for my family, for my children. I made the right decision across the board. I have no regrets."
It's no secret the sitting vice president has long coveted the Oval Office for himself. In 1988, his first run ended abruptly amid allegations of plagiarism. In 2008, with two more decades in the U.S. Senate under his belt, the then-Delaware senator threw his hat in again, but his candidacy never took off and he withdrew after Iowa.
But when the young Sen. Barack Obama needed to add foreign policy heft and an experienced political hand to his ticket, the Illinois senator looked to the chairman of the Senate Foreign Relations Committee who was 19 years his senior. Over the next eight years, Biden became a trusted adviser for the president, and the two forged a sort of father-son bond.
When the 2016 race ramped up, Biden was initially somewhat of an afterthought. Typically, the sitting vice president would be the natural choice to succeed a term-limited president. But Clinton was the early favorite after a near-miss in 2008, and progressives were also pushing for a champion of their own that they eventually found in Bernie Sanders.
But as the email scandal over the private server Clinton used at the State Department raged on, and her approval ratings continued to fall, there was a clamoring for Biden to reconsider.
Tragedy derails Biden's 2016 plans
Then, in May 2015, tragedy struck again for the man whose entire career had been marked by tragedy — his wife and daughter were killed in a car crash right after he was first elected in 1972, and he himself survived two aneurysms.
This time, his eldest son and political heir, Beau, the former attorney general of Delaware, died at just 46 of brain cancer. An initial deadline of summer 2015 to make a decision came and went, and any talk of the elder Biden's political future was understandably postponed.
Some supporters were still pushing for a Biden run, working to set up the infrastructure he might need. They argued that the sitting vice president had the necessary on-the-job training, decades of congressional experience and foreign policy chops, and could appeal to blue-collar voters and white men in places like Pennsylvania and Ohio — Hillary Clinton's Achilles' heel against GOP nominee Donald Trump.
"I look at someone who is a statesman. He's always someone who puts his country ahead of himself, and that's what we need right now," Will Pierce, the founder of Draft Biden, told NPR last year.
The image of Biden as America's bumbling yet lovable uncle, who always seemed to say or do the wrong thing at the wrong time, was a political asset, not a liability, others argued. He also had the ability to show enormous empathy, was a gifted retail campaigner, and was a passionate consoler during times of national tragedy.
"People want someone who's genuine, who does commit a malapropism from time to time," said Dick Harpootlian, a former South Carolina Democratic chairman who was urging Biden to run. "What they know is he's incredibly smart, he's incredibly genuine, and nobody knows how Washington works better than Joe Biden."
Ultimately, the grieving father never sounded like he was ready for the rigors of a national campaign so soon after such an unimaginable loss.
"I don't think any man or woman should run for president unless, No. 1, they know exactly why they would want to be president and, No. 2, they can look at folks out there and say, 'I promise you, you have my whole heart, my whole soul, my energy, and my passion to do this,' " Biden told CBS's Stephen Colbert during an emotional interview last September. "I'd be lying if I said that I knew I was there."
Biden's window closes
He never got there, at least not in time. A month later, with filing deadlines looming and Democratic debates underway, Biden confirmed in a Rose Garden speech, flanked by his wife, Jill, and President Obama, that the window "has closed."
His comments sounded like what would have been his stump speech, vigorously defending the Obama-Biden record and sounding a note of optimism.
"I believe we have to end the divisive politics. It's mean-spirited. It's petty," Biden said. "I don't think it's naive to talk to Republicans. I don't think we should look at Republicans as our enemy. They're the opposition, not our enemies."
"Most of all, I believe there's unlimited possibilities for this country," he added.
In the months since, the mood of the country has been anything but that hopeful plea, with Trump rising in large part due to fear and unrest. Last week in his acceptance speech at the Republican National Convention, he painted a grim picture of America.
Democrats have plenty of fissures, too, that were blatantly on display Monday, with infighting between Clinton and the establishment wing of the party and Sanders backers and a new progressive, increasingly vocal movement.
What if ... ?
Could Biden have fully bridged that gap if he were the Democratic nominee? Probably not. But for people turned off by a "Clinton dynasty" and their baggage — particularly independent voters — Biden would have offered a new, possibly more appealing choice. Early polls showed he was more competitive against leading Republicans than Clinton.
The two reportedly had a good working relationship while Clinton was in the Cabinet, but there was always a lingering jealousy of sorts from the vice president. As Politico put it in a story last August, the two were "frivals."
"He really likes her personally, but there's been always an undercurrent of resentment," a top Obama adviser told Politico. "I think there's always been an element of — and Biden is by no means the only one who has felt this — 'Why does she feel entitled to [run] and I can't?' "
Biden, like the president, kept his powder dry during the primary and joined Obama in endorsing Clinton after the last major primary contests were over. He told NPR's Rachel Martin last month that he would be "vouching" for Clinton over the course of the race. A planned July joint appearance in his hometown of Scranton, Pa., had to be postponed after the deadly police shooting in Dallas, but has been rescheduled for next month.
The 73-year-old has said he has "no intention" of running for public office again, and seems to have found a renewed vigor with the "Cancer Moonshot" he's spearheading.
As he toured the Wells Fargo Center on Tuesday, a day before his speech, Biden also did his part to tamp down the idea that the party was "fractured" between Clinton and Sanders allies and that more boos and jeers would permeate the remaining proceedings.
"I'd bet you anything I have that hardly anyone is going to pull the lever for Trump," he told reporters in typical Biden fashion. "C'mon, man."
"We have to be a little graceful here," he continued. "The Sanders delegates worked their tail off, and they're here in large numbers. They get a chance, man. I promise you, they're going to be fine."
But even if he's behind Clinton now, he confessed to ABC's Robin Roberts earlier this year that he thought about what might have been.
"I planned on running," Biden said in May. "It's an awful thing to say: I think I would have been the best president."