The debate comforted Clintonites but should have worried all Democrats. “If she didn’t do well against those guys, then God help our party.” Photo: Christopher Anderson/Magnum

On Wednesday, the day after the first Democratic presidential debate, almost the entire political and media Establishment was in agreement: Hillary Clinton had delivered a command performance, elevating her candidacy above the swamp of character concerns prompted by months of pseudo-scandal and political incompetence surrounding her email account. She had, it was widely acknowledged, dominated the stage and reassured anxious Democrats that she had the political skill to win. But at least one Democrat had a different reaction. “We woke up this morning, had our coffee, and went to work talking about Joe Biden and why his voice should be in the race,” says Josh Alcorn, a senior adviser to Draft Biden super-PAC.

Joe Biden is running for president — a fact that has been obvious, and true, for weeks. He spent the week continuing to phone key Democrats in early voting states and huddle with his kitchen cabinet, which includes his chief of staff, Steve Ricchetti; message man Mike Donilon; longtime adviser Ted Kaufman; and sister Valerie Biden Owens. He spoke with Harold Schaitberger, the general president of the powerful firefighters union, and won his endorsement, should he declare. According to a source, he told Schaitberger that “all the political pieces are in place.”

In effect, Biden has been running since Maureen Dowd published a Times column reporting how Biden’s 46-year-old son Beau implored his father to challenge Clinton for the nomination shortly before Beau died of brain cancer. The campaign picked up steam the following day when Alcorn, who had been a top strategist for Beau’s gubernatorial run in Delaware, joined the super-PAC. His arrival transformed what had been the fledgling brainchild of a 27-year-old former Obama volunteer into a serious campaign-in-waiting. Alcorn says they are “well on their way” to raising $3 million and have grown to 20 paid staffers that include veteran field operatives in Iowa, South Carolina, and Florida and a digital-data team. In September, it hired Mark Putnam, a veteran of Obama’s 2012 media team, to produce television ads.

Of course, what the Draft Biden PAC hasn’t had is Biden himself, and many Democrats believe that the vice-president has missed his window — that the debate went so well for Clinton she has effectively boxed him out. But this analysis assumes that Biden has been deciding whether he should enter. In reality, Biden is choosing what kind of campaign to run: an active one, in which he positions himself as a Clinton alternative, or a passive one that presents him as an alternative to Bernie Sanders or any of the other three non-­candidates who were onstage in Las Vegas.

Yes, the debate was comfortable to Democrats concerned about their front-runner, but it should also have been worrisome to Democrats concerned about their bench. “The fact she did well should surprise no one,” a Biden activist told me. “If she didn’t do well against those guys, then God help our party.” If something serious were to happen to Clinton — self-inflicted or not — the party would be entering a presidential race on favorable terrain but with a substantial talent problem. Martin O’Malley presented no rationale for a campaign; Jim Webb sounded bitter and bizarre; Lincoln Chafee at times appeared confused why he was even onstage. Sanders electrified his core supporters but didn’t suggest any newfound ability to sell his far-left platform to the general public. In a scenario where a Clinton campaign implodes, Democrats will again be desperate for a new candidate and will again review the options. Al Gore’s name will be floated. “Al Gore is doing nothing,” said a Democrat who sits on a board with him. Same with John Kerry. “John has not given the slightest indication he would do this,” Bob Shrum, who ran Kerry’s 2004 campaign, told me. What will be real is Biden.

If you look closely at Biden’s recent public activity, it looks very much like that of other candidates in the weeks before they declared. Most obviously, there has been no direction from him to shut down any talk of running. Launching a modern presidential campaign — even a late-entry one — requires planning; the day you declare, you need an operating website to receive donations and catch supporters, and those can’t be designed overnight. Looking indecisive is a classic stalling technique.

And while he is coy about mentioning a run in public, you can watch him positioning himself for either option: Clinton antagonist or replacement. Earlier this month, I went to see Biden on the stump at a nonprofit summit in a midtown ballroom. His remarks traced all the contours of a traditional campaign speech. He took aim at Clinton’s foreign-policy cred by noting he’s flown “more than a million miles” on Air Force Two and “met with almost every major head of state.” (He also said he’s known for speaking “the unvarnished truth.”) But the only candidate he invoked by name was Sanders. “I’m not Bernie Sanders,” he told the audience. “He’s a great guy, he really is. I’m not a populist, I’m a realist.”

Among Biden supporters, there is a range of opinions about how vulnerable Clinton is and how much it would be worth the effort (emotional, financial) to take her out. “The challenge for the vice-president is that there’s already an Establishment candidate in the mix,” Jared Bernstein, Biden’s former economic adviser, told me. “I think his calculus would be motivated by the extent to which she stumbles.” Competing against her is bound to be messy. There are whispers among some Clintonites that Obama’s loyalists — Valerie Jarrett’s name comes up — are encouraging Biden to run as payback for the ugly ’08 primary. “It goes back to that campaign,” a Clinton friend told me recently. Far easier would be to settle into the role as the Establishment’s insurance policy.

But for all the talk of Biden running out of time, the truth is he doesn’t need to rule out either strategy. Officially declaring his candidacy over the next few days will put him on all the primary ballots. “The thinking now is that they need to attend the Jefferson Jackson Dinner on the 24th,” a Bidenworld source told me, speaking of the timing of the announcement. Ted Kaufman, a Biden adviser who on Thursday emailed the vice-president’s former staffers to be prepared for a run, predicted “a campaign from the heart” that “won’t be a scripted affair.” One could imagine this translating into a campaign that begins heavy on Biden charm and light on attacking other Democrats — giving him more room to observe Clinton’s viability.

Or he may continue to delay an official announcement. This would bring his ghost campaign into uncharted waters, but there has never been a draft committee that’s gotten as far as the Draft Biden PAC. No matter what Biden decides, it can continue to operate, raising money and building potential voter lists. The deadline for entering the Georgia primary is October 29, but Biden could still run by not running, remaining a heartbeat away from the nomination. According to Democratic party rules, superdelegates could nominate him from the floor of the convention, which will be held in Philadelphia next July.

What’s clear is that he’s in the race: When a sitting vice-president works the phones after his party’s debate stressing that he is not ruling out running for president, that is the activity of a man running for president. Biden is the party’s Plan B, either its alt-Clinton or alt-Sanders, and he’s had loyalists like Alcorn to keep the campaign’s pilot light on while he decides which candidate to be.

*This article appears in the October 19, 2015 issue of New York Magazine.