Texas Democrat Rep. Lloyd Doggett calls on Biden to withdraw as presidential nominee

Texas Democratic Rep. Lloyd Doggett broke with President Joe Biden on Tuesday, calling on him to withdraw as Democratic nominee following the president's debate performance.

"President Biden has continued to run substantially behind Democratic senators in key states and in most polls has trailed Donald Trump. I had hoped that the debate would provide some momentum to change that. It did not. Instead of reassuring voters, the President failed to effectively defend his many accomplishments and expose Trump's many lies," Doggett wrote in a statement.

Doggett is the first sitting Democratic member of Congress -- House or Senate -- to publicly call on Biden to withdraw as the Democratic nominee for president.

"My decision to make these strong reservations public is not done lightly nor does it in any way diminish my respect for all that President Biden has achieved," Doggett said. "Recognizing that, unlike Trump, President Biden's first commitment has always been to our country, not himself, I am hopeful that he will make the painful and difficult decision to withdraw. I respectfully call on him to do so."

Doggett, who was first elected to the House in 1995, joins a growing cohort of Democrats who are criticizing Biden's debate performance and calling for the president to reconsider staying in the presidential race.

Former Ohio congressman and 2020 Democratic presidential candidate Tim Ryan wrote in an opinion piece published Monday night in Newsweek that Biden should step aside and that Vice President Kamala Harris should become the Democratic nominee for president.

"He also promised to be a bridge President to the next generation… Regrettably, that bridge collapsed last week," Ryan wrote of Biden's debate performance. "Witnessing Joe Biden struggle was heartbreaking. And we must forge a new path forward."

This is a developing story. Please check back for updates.

ABC News' Oren Oppenheim contributed to this report.