WASHINGTON — A broad and bipartisan group of senators is coalescing around legislation to create a high-level independent commission, modeled after the one that examined the Sept. 11 attacks, with broad powers to investigate the origins of the coronavirus pandemic and the response across the Trump and Biden administrations.

Under a plan proposed by the top Democrat and Republican on the Senate Health Committee — Senators Patty Murray of Washington and Richard M. Burr of North Carolina — a 12-member panel would have subpoena power to “get a full accounting of what went wrong during this pandemic,” Ms. Murray said in an interview, and make recommendations for the future.

The legislation, being circulated as a draft, is still in its early stages; Ms. Murray said she hopes to get feedback from colleagues within a month, followed by a hearing and a markup. In this highly polarized environment, both she and Mr. Burr acknowledged that politics could derail it.

And even if the measure passes both houses of Congress and is signed into law, the panel itself could become bogged down in bitter partisanship, depending on who is appointed to it.

But in interviews this week, more than a dozen senators from both parties embraced the idea, and none raised any substantive objections. More than half a dozen senators have similar proposals of their own that have produced some strange partnerships.

“I’m all for it,” declared Senator Roger Marshall, Republican of Kansas, a medical doctor who is working with Senator Kirsten Gillibrand, Democrat of New York, and others on a similar bill. “As a doctor, if a patient dies and we don’t know why, we do an autopsy. In the military, when we have a major event we go back and figure out what we did right and what we did wrong.”

The favorable reception from members of both parties is rare in a divided Capitol, and marks a significant turnabout. Bills introduced last year in both the House and the Senate, including one by Senators Susan Collins, Republican of Maine, and Bob Menendez, Democrat of New Jersey, have stalled, in part because Republicans feared they would target President Donald J. Trump’s early failures.

But now President Biden has been in office long enough to have had failures of his own. And by explicitly stating that the origin of the pandemic must be investigated, the Murray-Burr bill appeals both to Republicans, some of whom theorize the virus emerged from a lab leak in China, and Democrats who want to put that theory to rest.

“This is a crisis that has been shockingly polarizing,” said Philip D. Zelikow, the lawyer who led the 9/11 Commission and has been laying the groundwork for a pandemic inquiry. “This is the first signal that maybe leading Democrats and Republicans are now ready to come together. I think that’s really heartening. A lot of people would not have predicted it.”

The Murray-Burr bill is carefully drafted to avoid partisan divisions. The panel would be made up of 12 “highly qualified citizens” — preferably, but not necessarily, nonpartisan subject matter experts in relevant fields like public health, manufacturing of medical products, supply chain issues and national security. They may not be government employees.

Democrats and Republicans in Congress would each appoint half the members, who would name their own chairman and vice chairman. The White House would not make any appointments. The panel would hold hearings and take testimony, as the Sept. 11 panel did, and would be expected to produce a report within a year, with a possible six-month extension.

“I think it’s a splendid idea,” said Senator John Kennedy, Republican of Louisiana. “I think we need to know what worked and what didn’t work. I think we need to be prepared for the next one. I would particularly like to know whether the lockdowns and the shutdowns we saw, whether the flame was worth the candle.”

The measure avoids the use of the word “commission,” which acquired negative connotations in Washington after a bitter partisan debate doomed an effort to create a commission to investigate the Jan. 6 Capitol attack. Instead, the panel is called a “task force,” though Ms. Murray used the words “commission” and “task force” interchangeably.

“We tried to structure it in a way that would make a partisan approach difficult,” Mr. Burr said.

The proposal is part of a broader measure, the Prepare for and Respond to Existing Viruses, Emerging New Threats and Pandemics Act — or PREVENT Pandemics Act. It would require certain changes even before an inquiry has concluded, including making the director of the Centers for Disease Control and Prevention a Senate-confirmed position instead of serving at the will of the president.

People familiar with the authors’ thinking say they want to put the measure on a fast track, possibly by attaching it to another must-pass piece of legislation.

The Biden White House has been noncommittal. Jeffrey D. Zients, Mr. Biden’s coronavirus response coordinator, said this week that the administration was focused on the current crisis, but “over time we do look forward to engaging with Congress and reviewing lessons learned.”

But Dr. Anthony S. Fauci, Mr. Biden’s top medical adviser for the pandemic, said it was important to investigate the origins of the pandemic. He said it took years after the coronavirus that caused SARS emerged in 2002 to determine that it had almost certainly jumped from bats or civets to humans at a wet market in China. That led to greater regulation of wet markets, he said.

The 9/11 Commission, signed into law at the end of 2002 by an initially reluctant President George W. Bush, was an independent, bipartisan panel that spent a year and a half investigating the attacks and the country’s preparedness for them, holding public hearings in what amounted to a national reckoning.

It produced an extensive report in book form — both a detailed analysis and a gripping narrative that was a surprise best seller and changed Americans’ understanding of the attacks, which killed nearly 3,000, and the terrorist threat. The report led to structural changes in government and in the way intelligence is evaluated and shared, as well as new cooperation among federal, state and local agencies.

“We have prevented dozens of terrorist attacks in our city, because they work together,” Ms. Gillibrand said, referring to New York. “And so the same approach of a joint effort across government is necessary to stop the next pandemic.”

Mr. Zelikow, who led the Sept. 11 panel, has laid the foundation for a commission to investigate the pandemic, with financial backing from four foundations and a paid staff that has already interviewed hundreds of public health experts, business leaders, elected officials, victims and their families.

Mr. Zelikow, who has been consulting with Senators Burr and Murray, said he would be willing to turn his work over to a commission created by Congress. The pandemic has fundamentally challenged Americans’ trust in government, he said, and a thorough inquiry would be an important “bridge to trying to rebuild that confidence and that trust.”

Covid-19 victims and their families, many of whom support the idea of a commission, are also eager for the kind of airing of grievances that the Sept. 11 panel provided the victims of the terrorist attacks two decades ago. And, they say, a nonpartisan, serious inquiry might be something the country could rally around.

“I would like to see a narrative of what people have gone through to really help bring the data to life and to give a little bit of an on-ramp to healing for families and others,” said Kristin Urquiza, the founder of Marked by Covid, a victims group. “Right now we are so divided, but I firmly believe that through our loss and pain and grief, it’s actually an avenue toward seeing one another as humans and Americans.”