This combination of certainty and uncertainty was highlighted on a day when three states - Arizona, Florida and Illinois - held primaries and another - Ohio - that was scheduled to do so abruptly shut down its polling places for reasons of health safety. Nothing better described a new normal than the rapidly changing face of American politics in the age of a pandemic.
Voter turnout in the states with primaries fell below levels of previous elections, offset only partially by increases in early voting. Postponements of coming primaries continued to mount, causing the nominating season to be extended into later in June. The final primaries now could come only weeks before the Democratic National Convention is scheduled to convene in Milwaukee - if it is held as planned.
Squabbles among state and local officials, some partisan and some territorial, highlighted the tensions facing all government leaders as they attempt to preserve the sacred process of voting amid fears that the traditional methods of casting ballots now endanger voters and poll workers alike.
Calls for easier access to early voting or voting by mail also mounted on primary day as officials looked ahead not only to scheduled primaries but also to the November election that will be conducted, based on what federal officials have said, without a vaccine in place to help protect people from the virus. Those discussions are only beginning and will intensify, sometimes with partisan overtones.
From the start of the nomination battle, March 17, the day by which roughly 60 percent of all pledged delegates were to be allocated, was circled on the calendars of many strategists and campaign staffers as the day the contest could be settled and the party would know who its challenger would be to take on President Donald Trump in November.
That turned out to be accurate. For all practical purposes, the contest between Biden and Sanders is over. Numerically, the former vice president is still well short of a majority of delegates needed to win a first-ballot victory. But the reality is that it would take a radical change in fortunes for Sanders to start winning primaries by the margins he would need to catch up to Biden, let alone overtake him to claim the nomination.
The results on Tuesday underscored for the third straight week that Democrats have consolidated rapidly around Biden's candidacy and that Sanders has struggled to do as well this year as he did against Hillary Clinton in 2016. Biden's victory margins in Florida and Illinois topped those of Clinton's in 2016, in large part because Sanders was getting a smaller share this time than last. The results provided Biden with another big haul of delegates and an ever-widening advantage over Sanders.
This presents Sanders with a decision point he no doubt would rather defer as long as possible. Will he carry on with his candidacy against overwhelming odds or yield to the numbers both campaigns can calculate and suspend the campaign in the name of party unity and the goal of defeating Trump?
Pressure will mount quickly for him to end his candidacy and give Biden and the Democratic Party the freedom to shift their entire focus to the general election. But as Sunday's debate illustrated, Sanders isn't ready to give up fighting for the policies he has championed in this campaign and his bid in 2016, and without some assurances the decision will become all the more difficult.
The decision is complicated as Sanders ponders the impact of continuing or not continuing on the movement he has spawned among grass-roots progressives. Sanders long has talked about his candidacy as symbolic of a movement to change the country, and he has energized various groups on the left. He has been the leader of that movement since his 2016 campaign.
Biden will not make demands of Sanders, but neither will he wait for a decision one way or the other from his last remaining serious rival. His campaign already has moved to general-election footing, albeit it under circumstances that bring new challenges to the candidate and his staff. But he is mindful of the need to bring along those Sanders supporters who will be bitterly disappointed that their candidate will not be the Democratic nominee.
Biden spoke to that need when he addressed the country in a live-stream presentation, saying that while he and Sanders might differ on tactics, they shared many of the same goals. "Senator Sanders and his supporters have brought remarkable passion and tenacity to these issues, and together, they have shifted the fundamental conversation in the country," he said. "And let me say, especially to the young voters who have been inspired by Senator Sanders: I hear you. I know what is at stake. And I know what we have to do."
Biden entered Sunday's debate against Sanders hoping, if not certain, that the evening would be the beginning of a rapprochement between the two longtime Senate colleagues. Once past a mostly civil discussion about responding to the coronavirus, the tenor of the debate was hardly what the Biden camp had hoped for or expected. Sanders was on the attack. Biden, who does not like being challenged, fought back, at times testily.
That leaves Biden and his team with a delicate mission. As one campaign official, who spoke on the condition of anonymity to discuss the matter candidly, put it, "We're never going to let somebody distort Joe Biden's record. If [Sanders does so], we're going to push back on that. But the imperative of our campaign is to show Sanders' supporters that they have a home here. They're welcome as part of the Biden movement."
The backdrop of Biden's speech on Tuesday night was a fresh illustration of how rapidly the pandemic is forcing campaigns to change behavior. Last week, celebrating his victories, he spoke from the National Constitution Center in Philadelphia, with staff and some reporters present. On Tuesday night, he spoke from his home in Wilmington, Delaware, against a stark, darkened backdrop and two American flags.
Biden's speech from home, along with the poll workers wearing protective gloves and governors and mayors looking to change not just the dates of future primaries but also the way people will be allowed to cast their ballots in the future, represent the new state of politics that will exist for the foreseeable future.
With widespread and extraordinary measures being implemented to lessen the deadly impact of the virus, disruptions expand by the day and, as Tuesday showed, into all facets of life. In his remarks, Biden made a reference to twin challenges now confronting the nation, protecting the health and safety of the people and protecting the Democratic process at the same time - a test that no one was prepared for when the voting began less than two months ago.