Marc Caputo writes for Politico about the obstacles ahead for Democratic presidential front-runner Joe Biden.

Joe Biden reached a new and heady milestone when he shellacked Bernie Sanders in Florida, Illinois and Arizona to become the de facto Democratic nominee for president.

But there was no soaring speech to acknowledge the moment. He never took the stage amid a sea of Biden signs or before an adoring crowd on national television. Biden was instead stuck in a makeshift studio in his Delaware home, webcasting his remarks with a low-quality personal computer camera against a straight-out-of-YouTube black backdrop and two American flags.

He warned about the coronavirus contagion. He offered an olive branch to Bernie Sanders. Then, despite two consecutive weeks of smashing victories, he all but disappeared from the news cycle for days.

The moment was a perfect distillation of Biden’s current predicament — in a state of suspended political animation, trapped between a rival who refuses to quit and the global pandemic that has all but shut down the Democratic primary campaign.

Because Sanders won’t quit, Biden can’t fully pivot to the general election. He can’t truly unite the party’s warring factions. Nor can he begin stockpiling the vast amounts of money he’ll need for November. His momentum has effectively been stopped cold.

A source familiar with the Democratic National Committee’s discussions says the party offered both the Biden and Sanders campaigns the opportunity to open joint-fundraising accounts. But since Sanders declined, the party is reluctant to enter into one with Biden because of the bad optics of seeming to help one candidate.