US President Donald Trump calls himself a "wartime president" and former vice president Joe Biden says the nation must "put politics aside", but both have allowed their campaigns to launch personal attacks on the other in recent days.
The showdown comes as much of the presidential campaign has been either put on hold or shifted online as the contenders regroup for an new era of economic crisis and social distancing.
Fundraisers have been postponed, rallies have been cancelled, and new technologies are under consideration.
However, Mr Biden's sole challenger for the Democratic nomination, Senator Bernie Sanders, remains in the race.
Few are willing to predict how the events of the past few weeks will affect what is still expected to be a close election in November. But Democrats are hopeful the crisis will put into sharp relief the arguments they have been making for months.
Anita Dunn, a senior adviser to Mr Biden, said the American people were seeing in the pandemic response the consequences of "the chaos around this president".
"There is a price that this nation pays for that behaviour," Ms Dunn said. "As we move forward, that is going to be a case we prosecute."
Republicans, by contrast, are hopeful that Mr Trump's role as head of the federal response to the coronavirus will insulate him against the coming Democratic critiques about his leadership.
Mr Trump has told advisers that his daily news conferences are helping him because they show him involved, and advisers are hoping to utilise the video footage of New York Governor Andrew Cuomo praising the president in ads.
"Anybody who attempts to politicise and weaponise a public health crisis is revealed to be petty and peevish," said White House counsellor Kellyanne Conway.
Neither side has pulled its punches in near-daily diatribes. Mr Trump's campaign communications director accused Mr Biden of pushing critiques of Mr Trump that "dangerously undermine the federal public health effort by purposely sowing confusion and fears".
Mr Biden said Mr Trump "is falsely telling us he's taking action he has not taken, promising results he's not delivering and announcing actions that he has not even ordered".
Mr Biden's campaign also released a digital video accusing Mr Trump of adopting a "don't test, don't tell mindset".
As it adjusts to the pandemic, the Biden campaign has been scrambling to build out a new television studio in the recreation room of his Delaware home so he can communicate with voters - his first presentation is scheduled for Monday at 11.30am - and his staff is exploring technological solutions that would allow him brief interactions over video conference with individual voters that would imitate a rope-line encounter.
The campaign's immediate focus is on the policy response to the virus, but the political message focuses heavily on the Democratic case that Mr Trump has mishandled the crisis.
Mr Biden released a statement on Sunday calling on Democrats in the Senate to reject the stimulus bill being promoted by Senate majority leader Mitch McConnell.
"President Trump and Mitch McConnell are trying to put corporate bail-outs ahead of families," Mr Biden said, after the Senate rejected a procedural motion for the bill. "And it's simply wrong."
The attack builds upon a broader argument that the pandemic confirms concerns many potential swing voters have about Mr Trump.
Mr Trump's campaign advisers do see some liability in how the president handled the opening days of the virus -particularly in the lack of testing and the continuing slow response despite pleas from overwhelmed hospitals.
Some close to the president fear that if the stock market continues to drop, it would be difficult to reelect the president who has cast his central argument as a booming economy.
Mr Trump has sought to rewrite history in some ways, insisting that he was focused on the pandemic early even as he downplayed it publicly and ignored warnings about its potential.
He also is working to negotiate a large stimulus package that aides hope will have political benefits.
Trump advisers have been cheered by recent public polling that finds more than half of the country approves of Mr Trump's response to the crisis.