The first congressional Democrat has broken ranks and called on Joe Biden to withdraw his presidential candidacy following last week’s calamitous debate performance against Donald Trump. Lloyd Doggett, a House member for Texas, became the first Democrat in the House of Representative to urge the president to stop aside amid continuing signs of underlying alarm in the wider party over his electability triggered by his faltering display in Atlanta. As senior party figures continued to offer Biden public support even amid fevered behind-the-scenes concern, Doggett brought his own misgivings into the open, saying he had hoped last week’s debate “would give some momentum” to the president’s stagnant poll ratings in key battleground states. “It did not,” he said. “Instead of reassuring voters, the President failed to effectively defend his many accomplishments and expose Trump’s many lies.” He urged Biden to follow the path of a previous Democratic president, Lyndon Johnson, and announce that he would not accept the party’s nomination as candidate – a potential move commentators have dubbed as an “LBJ moment” (after Johnson’s full initials). “I represent the heart of a congressional district once represented by Lyndon Johnson. Under very different circumstances, he made the painful decision to withdraw,” Doggett said. “President Biden should do the same.” Johnson withdrew from the 1968 election race amid a a popular groundswell of opposition to the war in Vietnam and primary challengers in his own party, including from Robert F Kennedy, whose son is running as an independent candidate in the 2024 election and polling at levels that could further hurt Biden in a close race. Doggett – at 77, just four years younger than the 81-year-old president – praised Biden’s legislative achievements in office but said the time had come to hand over to a younger generation, pointing out that he had pledged during the 2020 election campaign to be a transitional figure. “While much of his work has been transformational, he pledged to be transitional,” he said. “He has the opportunity to encourage a new generation of leaders from whom a nominee can be chosen to unite our country through an open, democratic process. “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. “Recognising 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.” It remains to be seen if Doggett’s public stance will encourage other worried Democrats to put their heads above the parapet amid a steady drip of anecdotal and polling evidence that last Thursday’s CNN debate has had a corrosive effect on the president’s standing. A new poll in New Hampshire – a state Biden won by 10 points in 2020 – showed him now two points behind Trump since the debate. While Biden’s campaign have tried to frame the debate as one-off and pledged a fierce fightback, there have been mutterings of discontent within Democrat ranks. State governors – some of whom have been touted as potential replacements – have reportedly complained that Biden has not personally reached out to them since the debate, while similar gripes have been attributed to Hakeem Jeffries and Chuck Schumer, the Democratic leaders in the House and Senate respectively. Other ostensibly supportive figures, including the former House speaker Nancy Pelosi and Jim Clyburn, a representative from South Carolina, have issued statements that hinted at ambivalence. “I think it’s a legitimate question to say, is this an episode or is this a condition? When people ask that question, it’s completely legitimate – of both candidates,” Pelosi told MSNBC, adding that she heard “mixed” views on whether Biden was fit for the presidential campaign. In another sign of simmering discontent, Peter Welch, a Democratic senator for Vermont, criticised the Biden campaign for dismissing concerns over the president’s age as “bedwetters”. “But that’s the discussion we have to have,” he told Semafor. “It has to be from the top levels of the Biden campaign to precinct captains in the South Side of Chicago. … The campaign has raised the concerns themselves … So then to be dismissive of others who raise those concerns, I think it’s inappropriate.”