WASHINGTON — The chairman is in quarantine for coronavirus exposure. So are the star witnesses. But fireworks — albeit virtual ones — are likely when Dr. Anthony S. Fauci and three other top government doctors testify before the Senate Health Committee on Tuesday in one of the strangest high-stakes hearings in memory.
The session, in which the chairman and witnesses will appear by video, will be the first time Dr. Fauci, the nation’s top infectious disease expert — and one of the few truth-tellers in the administration in the eyes of many Americans — appears before Congress since President Trump declared the coronavirus crisis a national emergency on March 13.
At least in Washington, his return to the Capitol, though virtual, is going to be must-watch TV: a chance for Dr. Fauci and his fellow M.D.s — Robert Redfield, director of the Centers for Disease Control and Prevention, Stephen Hahn, the commissioner of the Food and Drug Administration, and Adm. Brett P. Giroir, the assistant secretary for health — to talk to Congress and the public unfiltered, without Mr. Trump hovering over them, cutting off questions or determining when they can speak.
Democrats are eager for that. “Dr. Fauci, let it rip,” Senator Chuck Schumer of New York, the Democratic leader, said Monday afternoon on the Senate floor.
In an emailed statement, Mr. Schumer said: “President Trump has either muzzled or contradicted what Dr. Fauci and other health experts have recommended to the American people. Tomorrow’s hearing is an opportunity for these experts to speak freely, and they must take advantage of it — because the country can’t afford to hear anything but the full truth.”
Mr. Trump, hoping to pre-empt Democrats’ questions about testing, announced Monday afternoon that his administration was sending additional money to states to beef up their testing capacity.
He and other administration officials have repeatedly boasted that the United States has done more testing than any other nation — more than nine million tests as of Monday morning, the officials said. That is a big increase from April: The United States conducted about 1.2 million tests from April 16 to 22, up from about 200,000 tests from March 16 to 22, according to data from the Covid Tracking Project.
Even so, many public health experts view the total number of tests as irrelevant. What matters, they say, is the percentage of the population being tested.
By those metrics, many states fall short of the necessary testing that must be conducted to reopen safely. The administration officials said states would be given enough tests to screen at least 2 percent of their populations for the coronavirus. But outside experts have recommended that anywhere from 0.9 percent to 50 percent of the American public must be tested for the coronavirus every week.
The issue is sure to come up at Tuesday’s hearing.
Senator Christopher S. Murphy, Democrat of Connecticut, said in an interview that he wanted answers on who in the administration was controlling supplies of testing. He said he had asked “over and over again for a detailed readout,” but has not received one.
“I’m still scared to death about the broken supply chain,” he said. “I don’t think they could have made a bigger mess of it than they have, but the continued lack of transparency about how the administration is intervening in the supply chain is maddening, and ultimately fatal.”
The hearing, which will begin at 10 a.m. and will be broadcast live by C-SPAN and streamed on the committee’s website, is titled “Covid-19: Safely Getting Back to Work and Back to School.”
The setting will be unusual to say the least, and it will underscore how far the nation is from normalcy. The panel’s Republican chairman, Senator Lamar Alexander, entered self-quarantine at his home in Maryville, Tenn., over the weekend after learning that an aide had tested positive for Covid-19, and will run the hearing remotely.
Two of the four witnesses — Dr. Redfield and Dr. Hahn — are also self-quarantining after being exposed to an employee at the White House who tested positive for the virus last week. Dr. Fauci on Sunday confirmed a CNN report saying he would enter a “modified quarantine” after a “low risk” exposure. With so many key players, including himself, stuck at home, Mr. Alexander announced over the weekend that all of the witnesses, including Admiral Giroir, who coordinates the testing effort, will also testify via video. Some senators may show up in person; others will videoconference in.
The setup of the hearing will mirror what senators did during a committee hearing last week, relying on the Senate video system to supplement in-person appearances. During that hearing, most senators participated remotely, appearing before backdrops of personal photos, their offices and homes.
That Dr. Fauci and the others are appearing at all is somewhat remarkable. The White House has barred him from testifying before the House, and the White House notified lawmakers last month that members of the president’s coronavirus task force could not accept invitations to testify on Capitol Hill without the express permission of the Mark Meadows, the chief of staff.
Emily Cochrane and Michael D. Shear contributed reporting.