WASHINGTON — (CNN) Vice President Joe Biden has personally made a series of calls this week to Democratic strategists from Iowa, New Hampshire and South Carolina, asking a final round of detailed questions about how — not whether — to launch a 2016 presidential campaign.

People familiar with the conversations tell CNN that Biden has been making the calls throughout the week, including on Wednesday, just as many leading Democrats argued the window to a potential candidacy was closing in the wake of Hillary Clinton’s strong performance in the party’s first presidential debate. He is asking these people to work for him if he runs.

The vice president has been making clear that his family is fully supportive of him jumping into the 2016 race, according to people familiar with the calls. They are guided by the belief that he has the best chance of keeping the White House in Democratic hands and he could forever regret taking a pass at another shot at the presidency.

The new round of calls this week — from the vice president himself, not simply his top advisers — suggest Biden is finally moving toward announcing a decision. He has been down this road before, inching close to a run but pulling back, so his next steps are far from certain.

A senior Democratic official tells CNN indications from the Biden inner circle are that the vice president will likely decide in the next three days. The official said they gave no indication what that decision would be. The source said there is a sense of growing impatience among some Democratic officials over the uncertainty.

Former Delaware Sen. Ted Kaufman, a member of Biden’s close inner circle, sent an email late Thursday to a network of Biden alumni, obtained by CNN, saying that while he doesn’t know when Biden will decide, he knows Biden is aware of the ticking clock.

“On the second question – timing – I can’t add much, except I am confident that the vice president is aware of the practical demands of making a final decision soon,” Kaufman wrote. “He has been in public and political life a long time and he has a good grip on the mechanics around this decision.”

Biden is still leaving the impression this week that he wants to join the race, people familiar with the calls say, and does not seem dissuaded by the argument that he could complicate the party’s nominating fight or damage his own reputation.

“His family is totally on board,” one top Democrat who has spoken to Biden this week told CNN, speaking on condition of anonymity to discuss the private conversation. “He wants to do this.”

Kaufman did not in his email prognosticate on whether Biden would jump in, but wrote about what he thought might go into his decision making. He said family support was crucial and that Biden would run an “optimistic campaign.”

“If he runs, he will run because of his burning conviction that we need to fundamentally change the balance in our economy and the political structure to restore the ability of the middle class to get ahead.

And whether we can a political consensus in America to get it done,” Kaufman wrote.

The question of whether he has waited too long comes up in the conversations, people familiar with his calls say, which could be the most important remaining consideration in his decision. It could also provide an exit strategy for him if he ultimately decides against running after doing little to quiet weeks of speculation.

The arguments in favor of running, according to people who have spoken with the Vice President and his team of advisers, include:

He would have full access to the vaunted Obama campaign email list, since Biden is effectively a part owner since he was on the ticket in 2008 and 2012.

A handful of influential labor unions have not yet endorsed a Democratic candidate, including international unions representing the firefighters, steelworkers, SEIU and Teamsters.

One potential point of entry into the race comes October 24 at Iowa’s Jefferson-Jackson Day Dinner, when thousands of party activists will descend on Des Moines. If he decides to vigorously campaign for the Iowa caucuses in February, his supporters believe this is a moment that shouldn’t be missed, given the high-profile event is attracting the rest of the party’s top candidates.

Yet a Biden candidacy is also challenging. The campaign has moved quickly – even more so in recent weeks – and Biden would have to work to compete with his fellow Democrats at that Iowa dinner. It’s remembered for being a break-out moment for Obama in 2007.

But Katy Perry is scheduled to perform for Clinton that night. The question is whether Biden can compete — or catch up — with a race that’s been underway for months.

Biden himself teased the press earlier Thursday when he was repeatedly asked about whether he would run for president. “I’ll talk to you all about that later,” Biden told members of the media earlier in the day, after laughing at their 2016-related questions.

Kaufman closed his email by reminding Biden alums that they could be called upon — and soon.

“I know in the daily ups and down of the political swirl, we all get bombarded with the tactics. So sometimes it’s good to take a step back and get real again,” Kaufman wrote. “Let’s stay in touch. If he decides to run, we will need each and every one of you — yesterday!”

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