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He feels bound by no firm deadline, several Democrats close to him still say, yet he understands he may soon begin testing the party's patience.
As the five declared Democratic presidential candidates descend on Las Vegas for the first debate of the year Tuesday, Biden plans to remain in Wilmington for a final day before returning to Washington. He is likely to watch on Tuesday night, aides say, although they insist his decision will not be influenced by the debate's outcome.
Some friends who have spoken to him in recent days have walked away with the impression that he is leaning toward running
, even though his aides insist he has not yet reached a final verdict. He's made little secret of the fact that he would like to run, but family concerns are still front-and-center in his decision-making process.
A presidential candidacy was discussed throughout the weekend, including at a family dinner on Sunday night at the Biden home, but two people close to the vice president said 2016 campaign deliberations did not dominate the talks.
The only real deadline facing Biden is the fight for delegates, which is a critically important one, as the 2008 Democratic presidential race between Barack Obama and Hillary Clinton illustrated.
Georgia has the earliest deadline. By October 29, presidential hopefuls must send a letter declaring their candidacy to the state party, which passes forward a slate of candidates for the Super Tuesday primary on March 1. Several other states have deadlines in early November to qualify to be on the ballot, including Texas, Arkansas and New Hampshire.
A mid-October announcement would be enough time for Biden to jump in, election lawyers say, but anything later in the month would make it difficult to put together the structure of a campaign organization.
For Democrats, it's the biggest uncertainty in the party's presidential race.
President Barack Obama declined to weigh in on a potential Biden candidacy speaking on CBS' "60 Minutes" in an interview aired Sunday.
"I am going to let Joe make that decision," he said.
But he showered Biden with praise.
"I think Joe will go down as one of the finest vice presidents in history and one of the more consequential," Obama said. "I think he has done great work. I don't think there's any politician at a national level that has not thought about being the president. And if you're sitting next to the president in every meeting and, you know, wrestling with these issues, I'm sure that for him he's saying to himself, 'I could do a really good job.'"