The subject of growing presidential chatter this week after reports emerged his aides were making preliminary moves toward a run, Biden hasn't yet made up his mind on launching a campaign.
No one he's spoken with can say whether the vice president is leaning one way or the other. And the grief he felt in the immediate aftermath of his son's death this summer is far from gone.
But as Washington quiets down for the steamy August lull, Biden will soon decamp for a family vacation to gauge his loved ones' interest -- and willingness -- for a third presidential bid.
And while he's vacationed there often, Biden's choice of getaway spot -- Kiawah Island, South Carolina -- certainly won't quiet any speculation about a presidential run.
Enthusiasm for a run from his sons -- including from the late Beau Biden, who before his death encouraged his father to launch a bid -- will be a factor.
But it's the opinions of his wife and sister that Biden's confidantes expect to carry the most weight.
Second lady Jill Biden, who hasn't spoken recently about the chance of a third Biden presidential run, did appear open to the possibility of her husband mounting another campaign for president during a 2012 interview with USA Today.
"I've learned through many, many, many elections that you just take it one step at a time," she said then. "Sometimes when we've folded our tents and gone, I'll say, 'Joe, never again; we're never doing this again.'"
"You know, things happen for a reason," she added.
Biden's sister Valerie, a top political adviser who helped run his 2008 presidential campaign, told Delaware Online this week she hadn't spoken to her brother about making another bid.
"He'll decide when he decides," she said.
The other opinion Biden is likely to value: Obama's. The two men have grown close over the course of their White House tenures, and although he won't be able to endorse a candidate in the Democratic primary, or even appear to lean toward one, Obama's aides expect his private political advice to be sought both by Hillary Clinton and Biden.
The vice president may have received that guidance this week when he and Obama sat down for their weekly lunch, though the precise contents of their conversation are known only to them.
"I suspect they covered a variety of topics -- some personal, some public, as they relate to ongoing debates," White House Press Secretary Josh Earnest said. "I wouldn't be surprised if there was maybe even some politics discussed."
For Biden, a deadline of sorts for declaring his candidacy was established this week when the Democratic National Committee announced its schedule of primary debates. The first forum will come Oct. 13 at a CNN-sponsored event in Nevada.
As of now, five declared candidates are expected to appear: Clinton, Vermont Sen. Bernie Sanders, former Maryland Gov. Martin O'Malley, former Rhode Island Gov. Lincoln Chaffee and former Virginia Sen. Jim Webb.
If he were to become the sixth contender on stage, Biden's supporters would look for him to become the main foil to frontrunner Clinton, even as the race's newcomer.
Though he's not a declared candidate, and could pass on a bid, Biden has been kept informed on the Democratic debate process by party officials.
"We have, actually, throughout this process, been briefing and keeping up to speed potential and declared candidates for president. And we know all of our candidates were at one point a potential candidate," Democratic National Committee chairwoman Rep. Debbie Wasserman Schultz told CNN on Friday.
"So, yes, we briefed the vice president's team," she said. "He's not ruled out the possibility of running for president and he's the sitting vice president of the United States of America. Of course he'll be welcome if he decides to run."