Biden’s Team Scrambles to Contain First Democratic Defections

President Biden and his advisers rushed to stem the first serious defections inside the Democratic Party since his shaky debate last week, as leading Democrats lent legitimacy to questions about his mental acuity and raised the specter of replacing him atop the ticket.

Mr. Biden’s operation hoped to assert fresh control on Wednesday, holding a call with a group of Democratic governors, in person and virtually, as he seeks to shore up support after days of private hand-wringing went public in sudden and quick succession.

On Tuesday, Mr. Biden suffered his first formal call to resign from the race from a Democratic member of Congress. The key Black lawmaker whose endorsement helped lift Mr. Biden to the nomination in 2020 said he would back the vice president if Mr. Biden “were to step aside.” And former House Speaker Nancy Pelosi said after Mr. Biden’s halting debate performance that it was “a legitimate question to say, ‘Is this an episode or is this a condition?’”

For days, the Biden campaign has insisted privately to donors and party activists and in memos that the race remains unchanged. But a private set of polls from a pro-Biden super PAC leaked to the news site Puck showed the president losing ground — around two percentage points — across all the most important battleground states. He was also now trailing in New Mexico, New Hampshire and Virginia, three states that were not seen a year ago as likely even to be contested seriously by Republicans.

The spate of early defections and diminished support in surveys demonstrates the scale of the crisis still gripping the Democratic Party. Though Mr. Biden’s aides have forcefully and repeatedly said publicly that the president has no plans to leave the race, the first public