The gaffes keep piling up: the untimely comments stoking fears of swine flu, dismissals of Russia that seem straight out of the Cold War.
But in defiance of the normal rules of American politics, Vice President Joe Biden appears to be solidifying his relationship with his boss and accumulating more assignments central to the administration's agenda.
Having lined up support in the Senate to assure passage of the $787-billion economic stimulus plan, Biden was recently tapped by President Obama to play a bigger role in the healthcare debate that is now dominating the congressional agenda. He is at the table on major foreign policy issues and has been asked to oversee the stimulus spending effort.
"For the president to give him the single largest initiative to date [the stimulus] with all the potential risks and pitfalls attached, speaks to a level of trust that's quite real," said Anita Dunn, White House communications director.
Steadily, Biden has tried to prove his value to the administration as a well-connected insider and a trusted advisor who won't reveal confidences.
When the White House was working to pass the stimulus bill, Chief of Staff Rahm Emanuel handed Biden a list of six Republican senators to call. Biden has sought to keep old Senate friendships intact, inviting members to his residence and hanging on to his locker at the Senate gym.
Biden met with the six and called them repeatedly. In the end, "we got three -- which wound up being the difference," said Ron Klain, Biden's chief of staff.
Still, the transition to the No. 2 job has been rough for Biden. His habit in the Senate was to expend torrents of words in a bid to stand out. What's different now is that every word counts -- and foreign leaders are paying attention.
The exuberance and indiscipline at the root of Biden's well-publicized gaffes can have serious consequences. In April, amid fears of a swine flu pandemic, he told a TV audience that he had advised his own family not to travel in confined planes or trains.
The White House quickly issued an apology, and the travel industry put out a statement cautioning that politicians shouldn't pose as medical experts.
Puzzling over his comments on foreign policy, other countries are wondering if Biden speaks for the administration and if not, who does?
Biden stirred a tempest in the Kremlin last month when he told the Wall Street Journal that Russia would be forced to bow to U.S. wishes because of its "withering" economy, shrinking population and backward-looking leadership.
Secretary of State Hillary Rodham Clinton felt obliged to correct the record the next day, saying that the administration viewed Russia as a "great power."
The Russian elite generally interpreted the comment as a sign that the administration's professed interest in a "reset" of relations with Moscow -- announced by Biden himself -- was insincere.
Andranik Migranyan, a former advisor to Boris Yeltsin, said that "the urgency of the correction by Clinton and the White House shows Russian leaders that Biden isn't taken seriously even by the Obama administration itself."
"I don't want to be rude, but if he continues these kinds of comments, he will be perceived as a clown, and no one will take him seriously," said Migranyan, who now heads the New York office of the Institute for Democracy and Cooperation, a think tank funded by the Russian government.
Valerie Jarrett, a senior advisor to Obama, said in an interview that Biden's verbal missteps are forgivable: "We all have to have our words clarified at times. That's part of what makes the vice president so endearing. Everyone says, 'Oh, my gosh. I could have said that.' And the press tends to overblow it. We wouldn't change him one bit."
Some who've known Biden for years say he has picked up new habits. "Joe's on the teleprompter a lot more than he was at the beginning," Pennsylvania Gov. Edward G. Rendell said.
Yet Biden is still valued in settings where he can be himself. It was no accident that Biden was invited to Obama's "beer summit" last month to smooth over the arrest of Harvard University professor Henry Louis Gates Jr.
"If you said to me, who's the person in the administration you'd most like to have a beer with, Joe Biden would be the guy most Americans would choose," Rendell said.
In Obama's world, Biden's flaws and attributes are no secret. Even as officials in the Obama campaign considered adding Biden to the ticket, they knew what they were getting into.
"You knew what was in the box," said one Obama campaign advisor. "Everyone understood the benefits and relative" -- here, he paused -- "challenges that come with Biden."
Current and former administration officials could not cite instances in which Biden's opinion has carried the day on a foreign policy decision, but they say he plays a major role in the discussions. They say he has deep knowledge of foreign affairs, personal relationships with presidents and kings, and a finely tuned sense of how the American public views foreign policy.
In his most visible act as the administration's "point man" on Iraq, he traveled to Baghdad earlier this year to deliver a tough message that if the Iraqis didn't move to political reconciliation, the U.S. would end its involvement.
In the internal debates this spring that led to the administration's new policy on Afghanistan and Pakistan, Biden joined others at the table in pushing to limit the number of additional troops in Afghanistan, and sought to focus the counterinsurgency mission more on Al Qaeda, and less on other militant groups.
A former senior U.S. official who was present said Biden, conscious of the Americans' limited patience with war, "asked a lot of questions: How much were we committing to? How many troops could all this amount to?"
Biden wanted to make sure that the administration's ambitious plans for nation building, and the military leadership's concern about the huge demands of the task, didn't lead to a classic quagmire, this official said.
"He asked the Vietnam question," he said.
Ultimately, the president opted for a troop level higher than Biden had advised.
Biden associates say his relationship with Obama is evolving. Coming to the political partnership with no real friendship to speak of, Biden has sought to cultivate one with Obama since the swearing-in. A Biden aide calls the process a "courtship after the marriage."
One White House official recalls the vice president fretting over what to get Obama for his 48th birthday earlier this month. Biden wanted to go with a Nintendo Wii. Told that Obama's daughters already have one, a disappointed Biden said, "You're kidding." Instead, he went with a golf range-finder to help the president judge distances to the hole.
Biden's practice is to do what he's asked. He has traveled frequently to battleground states important to Obama's reelection. Travel records show he has spent five days in Pennsylvania; a total of six in Colorado and North Carolina; and four in Virginia.
A comparison to other vice presidents shows Biden taking on a larger role than some high-profile Democratic predecessors. There is no comparison to George W. Bush's vice president, Dick Cheney, whose broad portfolio made him a virtual co-president. But one could argue that Biden is more influential than Al Gore, whose primary assignments -- reinventing government and global climate change -- were not necessarily at the heart of Bill Clinton's agenda.
Gore did not interview Supreme Court candidates. Biden did. As a former Senate Judiciary Committee chairman who has presided over volatile nomination hearings, Biden also spoke informally to Sonia Sotomayor about what she might expect in her star turn before the panel.
Biden's ambitions go beyond serving as an influential vice president. He doesn't necessarily believe his political career has peaked.
Aides said he might go for the Democratic presidential nomination in 2016. He would be 74 upon taking office, but his staff insists that's not too old.
"He's incredibly fit, vigorous man of his age, and it's impossible for me to imagine that he won't be in public service in 2017 in some form," a Biden aide said.
Times staff writers Mark Z. Barabak in San Francisco, Richard Boudreaux in Jerusalem, Megan K. Stack in Moscow and Borzou Daragahi in Beirut contributed to this report.