Biden doesn’t have the delegates to clinch the nomination. That could change June 2.

Nearly two months after his last opponent dropped out of the race, former Vice President Joe Biden is poised to formally clinch the Democratic presidential nomination in early June, possibly as soon as Tuesday, when a number of states will hold primaries that were delayed by the coronavirus pandemic.

Biden has been referred to in the press as the “presumptive nominee” ever since Sen. Bernie Sanders of Vermont ended his White House bid in early April, but at the time Sanders dropped out, Biden had not yet amassed the 1,991 delegates needed to formally secure the nomination. 

In the eight weeks since Sanders suspended his campaign, Biden has been thrust into the unusual position of being the de facto winner of a primary race that is all but finished, though technically not over under the rules of the Democratic National Committee. 

Eight states and the District of Columbia are holding Democratic presidential primaries Tuesday, putting a total of 500 delegates up for grabs. Biden, having already won 1,556 delegates, needs just 425 more to cross the threshold for winning the nomination.

But despite having no official competitors, it’s possible Biden will come up just short.

Biden has won 80 percent of the delegates in the eight states that have voted since Sanders left the race on April 8, but Sanders still captured the remaining 20 percent, and has 1,007 delegates entering the June 2 primaries. 

When Sanders dropped out of the race he vowed to stay on the ballot through the end of the primaries in order to win as many delegates as possible and influence the party’s platform at the nominating convention this summer.

If the pattern from April and May holds and Sanders wins roughly one-fifth of the delegates, Biden would fall a few dozen delegates short of clinching the nomination Tuesday. In that case, the former vice president would have to wait until the next round of voting on June 9, when he will most likely get the delegates he needs to become his party’s official nominee.

“After June 2, or whenever he crosses that threshold, it’s going to give Biden an opportunity” to bring attention to the 2020 presidential election at a time when most voters have been focused on the public health crisis and ensuing economic fallout, said Floyd Ciruli, a nonpartisan pollster based in Colorado.

Whenever Biden finally clinches the nomination it will represent a milestone for his campaign. Biden consistently led the crowded primary field in national polls after entering the race in April of last year, but he has struggled with questions about his age and legislative record. His campaign appeared in trouble after Biden did not win the first three nominating contests in Iowa, New Hampshire and Nevada. But then he won South Carolina, launching a comeback that eventually forced the rest of his rivals out of the race.

Celebrating the occasion will be tricky. With large public gatherings still banned in most states, Biden cannot hold a campaign rally to mark the moment. He has been stuck at his home in Wilmington, Delaware, where he makes media appearances and holds virtual events with supporters.

How he frames his victory will be critical, said the historian Dan T. Carter. If Biden comes across as too self-congratulatory, he risks putting off voters who are still focused on the pandemic.

“The last thing Americans want to see is someone who assumes they’re going to be elected and takes it for granted,” Carter said.

Nancy Mills, the chair of the Pennsylvania Democratic Party, said in an interview that she expects Biden will show restraint when he clinches the presidential nomination. “I don’t think there’ll be any arrogance or a victory lap,” Mills said.

Mills argued that Trump’s much-criticized response to the coronavirus has helped Democrats unite and put aside the ideological battles of the primary cycle, and pave the way for Sanders supporters to get behind Biden.

“I think we’re all aware of what’s really important. The pandemic and the reaction from president Trump has been a wake-up call,” she said.

Pennsylvania will play a big role in determining whether Biden crosses the delegate threshold on Tuesday — it has 186 delegates, by far the largest number of any state voting this week. Maryland, the state with the second-largest number of delegates Tuesday, has 96.

The other states voting Tuesday are Delaware, Indiana, Rhode Island, South Dakota, New Mexico and Montana. Of those, just three — South Dakota, New Mexico and Montana — had originally planned to hold their Democratic presidential primary on June 2. Washington, D.C., was also already scheduled to vote June 2.

The rest, including Pennsylvania, were supposed to vote earlier in the year but delayed their primaries because of public health concerns around COVID-19.

After Tuesday, seven states are planning to hold primaries between June 9 and Aug. 11. The Democratic National Convention, where Biden will receive the formal nomination for president, is scheduled to take place in Milwaukee at the end of August. The format of the convention, which would normally entail the gathering of tens of thousands of attendees in a crowded arena, remains unclear as the DNC contends with social distancing guidelines meant to slow the spread of the coronavirus.