CHARLOTTE, N.C. — For officials who fretted about whether Joe Biden's avuncular style could be tamed by the trappings of the vice presidency, it was an inauspicious beginning.
Barely 48 hours into the Obama-Biden administration, the new president ceded the microphone to his partner for a brief task: swear in members of the senior staff. After a bit of confusion, Biden made a crack at the expense of Supreme Court Chief Justice John G. Roberts Jr., who had transposed words of the presidential oath two days earlier.
As the audience groaned, President Obama tapped Biden on the arm and shook his head. It was an unmistakable signal, and a reminder of why both men and those around them had their doubts about whether the unlikely partnership could work.
Three and a half years, more than 800 joint Oval Office meetings and nearly 100 one-on-one lunches, a Recovery Act and healthcare law later, the doubts have disappeared.
Despite the initial public flap, and others that would follow, aides to both men say that Obama has found Biden to be an indispensable advisor, playing the role the two had sketched out when the junior senator chose his more seasoned colleague as his running mate.
What fused the partnership was the Biden quality Obama and his team have come to prize more than anything else: loyalty.
"No matter what ... no matter the issue, no matter what happened, all the precedent, Joe Biden will have the president's back, and will be one of, if not the most, forceful advocate on behalf of the president, his policies, and the decision," said Rahm Emanuel, Obama's first chief of staff and now mayor of Chicago.
It is that sentiment that pushed the decision, breaking from recent tradition, to have Biden speak Thursday at the Democratic National Convention, just before Obama will accept his party's nomination for a second term.
In his speech, Biden will speak of the countless hours he has spent at Obama's side during some of the most trying moments of their time in office, offering the kind of insight into his tenure that few else can match.
When Biden addressed party delegates in Denver four years ago, he did so with only an aspirational notion as to what his role would be. The two men had been colleagues for about three years, and competitors for the presidency for much of 2007.
"When the president asked me [to join the ticket], I asked why he wanted me to do the job. I admit to you, I even wondered," Biden said in an interview.
Obama told Biden he wanted him to "help me govern." Biden accepted the invitation, he said, with a few stipulations: He wouldn't "wear any funny hats" or "change his brand."
"He asked me whether I wanted a portfolio. I said I don't want one. Give me assignments that have a sell-by date. Let me use what experience I have to do things I deal with that I'm relatively — hopefully — competent at," Biden said.
And he wanted to be the last guy in the room with the president before Obama made a tough decision. Biden said the president has been true to his word.
"There really is a close working relationship and a great deal of trust. And that's what I signed up for," Biden said.
Given the severity of the challenge Obama faced after winning election, there would be no honeymoon period for the two.
With so much on Obama's plate, Biden drew major tasks early on. Most prominently, that included making a fresh assessment of the situations in Iraq and Afghanistan, a task Biden set to while still vice president-elect and chairman of the Senate Foreign Relations Committee. (Ending the war in Iraq was among Obama's marquee pledges as a candidate.)
"The president said we really need sustained focus from the White House on this. And then he turned to the vice president and said, 'Joe, you know Iraq better than anyone in our administration. You should do it,'" said Tony Blinken, the vice president's national security advisor.
On the domestic front, Biden was the point man for pushing through Congress the American Recovery and Reinvestment Act, or the economic stimulus. Overseeing the tricky proposition earned Biden the moniker "Sheriff Joe."
The challenge of passing the legislation in the first place, even with significant Democratic majorities in both chambers, would demonstrate the extent to which Obama would rely on Biden's institutional knowledge and relationships on Capitol Hill to pass his agenda.
"He was the one guy who all the parties trusted," said Jim Messina, who served as deputy White House chief of staff before leaving to run the president's reelection campaign.
Biden took on a similar role in the debate over the healthcare law — which at times meant absorbing the frustration of former colleagues who were reluctant to bring it to the president himself.
On one occasion in 2009, in the early stages of the legislative battle, both Obama and Biden addressed Senate Democrats at the White House to discuss strategy. While both men were present, the reception was polite. But when Obama excused himself, the lawmakers became more candid.
At one point, Biden drew a firm line, making it clear that if any of the private resentments became public, the legislators would have Biden to answer to. That account soon made its way to the president, who went to the vice president's office to thank him.
Few of Biden's private moves, however, have gathered as much attention as his occasional public gaffes. In May, Biden was seen as putting Obama in a tough position when he came out in support of gay marriage earlier than the president. (Obama soon followed suit.) More recently, Biden drew groans for telling a partly black audience that Republicans wanted to "put y'all back in chains."
So ingrained is the public perception that Biden is something of a goof, Republican image-meister Frank Luntz said, that in focus groups the mere mention of the vice president's name almost always spurs laughs — from supporters and critics alike. A Pew survey released Wednesday asked voters to offer a one-word description of the vice president, and for every "good" and "honest" there was "idiot" and "buffoon."
Still, Biden is clearly relishing a deep connection with Obama. At campaign stops throughout the country, Biden has taken to referring to Obama as "my guy," as much as he uses the elected title.
"We were good acquaintances before we got elected. But we've become, as he says, I'm like his older brother. We've become truly good friends," Biden told voters at a campaign stop in Durham, N.C., last month. "I wish like hell I wasn't his older brother!"