Joe Biden took the stage at his Thursday night news conference with everything on the line: his presidency, his re-election hopes, and his political future. However, he barely acknowledged these high stakes during the hour-long session, which marked the end of a NATO summit. Earlier, he had mistakenly introduced Ukraine’s President Zelensky as “President Putin” at a separate event.

This news conference was his first unscripted appearance since a disastrous debate with his rival Donald Trump, which led to calls from several Democratic politicians and donors for him to withdraw from the race. At 81, Biden has faced continuous questions about his age and ability to serve another term, especially after the debate.

At the highly anticipated news conference, Biden dismissed concerns about his campaign posed by a room full of reporters. He promised he was fighting not for his legacy but to finish the job he started in 2021. “If I slow down and can’t get the job done, that’s a sign I shouldn’t be doing it,” he said. “But there’s no indication of that yet.”

Depending on perspective, this could be seen as either dogged determination or denial about his dire situation. Minutes after the news conference, several more Democratic members of Congress publicly called on Biden to step down, joining at least a dozen other lawmakers from his own party.

The question now is whether the floodgates will open or if the tide will hold. Biden’s situation was not helped by two excruciating gaffes during the conference. In his first answer, he called his own Vice-President Kamala Harris “Vice-President Trump,” a painful mistake in front of a national television audience. This came just an hour after another error at a NATO event, when he introduced Ukrainian President Zelensky as “President Putin,” prompting loud gasps from the audience.

Biden quickly corrected the first mistake involving Ukraine’s leader, but did not catch the second one, even as reporters murmured and his top Cabinet secretaries sat stone-faced. These moments, the only major stumbles in an otherwise steady appearance, will surely prompt nervous Democrats to wonder if more gaffes are to come.

Despite this, Biden appeared determined, laughing and smiling as he answered questions. He insisted he could keep up with Russia’s Vladimir Putin and China’s Xi Jinping, even though a lingering hoarseness and cough from the debate were still apparent. He reiterated that he didn’t need cognitive tests, telling reporters that even if he saw “two doctors or seven,” his critics wouldn’t be satisfied.

The election campaign, he said, had barely started, and he expressed confidence in beating Donald Trump in November’s election. He also mentioned that Democratic delegates who will back him at the party’s convention next month are free to change their minds, before mock whispering: “It’s not going to happen.”

Biden said he would consider stepping aside if his staff provided data showing he couldn’t win, but polls still show the race as a dead heat. An Ipsos survey released earlier on Thursday had Biden only one point behind his opponent, well within the margin of error. Despite unprecedented drama surrounding both candidates, support for them has remained remarkably stable.

However, polling alone won’t calm the panic among many Democratic officials, and the storm clouds around Biden’s campaign won’t be easily dispelled. More Democratic politicians are reportedly poised to announce their break with the president, waiting until the conclusion of the NATO summit to voice their concerns.

This is just the first round of tests for the embattled president. He has another high-profile sit-down interview with NBC’s Lester Holt on Monday. Donors are anxious, and several reports suggest that even figures within Biden’s own campaign are plotting ways to usher him toward the exit.

Despite all this, Biden made it clear that prying the nomination away from him will be a challenging task. The 81-year-old man who at times gripped the lectern with two hands and insisted he was the “best-qualified person” to run the country is not going to exit the stage quietly.