President Biden warned on Monday that the Supreme Court’s decision on presidential immunity meant that there were “virtually no limits on what the president can do” and urged voters to prevent former President Donald J. Trump from returning to the White House freed from the constraints of the law.
“The American people must decide if they want to entrust the president once again — the presidency — to Donald Trump,” Mr. Biden said during brief remarks, “knowing he’ll be more emboldened to do whatever he pleases whenever he wants to do it.”
Mr. Biden’s response to Monday’s court ruling was his first public remarks since he spent the weekend hunkered down with family at Camp David. His disastrous debate performance in Atlanta last week has led some Democrats to call for him to drop out of the presidential race because of concerns about his age and mental fitness.
The president appeared ruddier than he did during the 90-minute debate, when many observed that he looked very pale. He did not stumble over his words on Monday or falter midsentence. But he was using a teleprompter for the remarks, which lasted about four and a half minutes.
Mr. Biden also did not respond to several shouted questions at the end of the remarks on Monday, including one asking whether he intended to drop out of the race.
The Supreme Court ruled on Monday that Mr. Trump has significant immunity against prosecution on charges of trying to overturn the 2020 election. Mr. Biden called that a “dangerous precedent” that fundamentally alters the longstanding belief in the United States that no one should be above the law.
“I know I will respect the limits of the presidential powers, as I have for three and a half years,” Mr. Biden said on Monday night. “But any president, including Donald Trump, will now be free to ignore the law.”
Mr. Biden said he agreed with Justice Sonia Sotomayor, who wrote that “with fear for our democracy, I dissent.” Mr. Biden echoed her language as he concluded his remarks.
“I dissent,” he said. “May God bless you all and may God help preserve our democracy.”
Mr. Biden’s response signaled that he intended to focus his campaign on the issue of Mr. Trump’s criminal cases, which have been a central part of the president’s argument for re-election. During a rally on Friday, he cited the numerous court cases against Mr. Trump as proof that he is a “one-man crime wave.”
But the president’s appearance in the Cross Hall of the White House, the stately venue used for many previous addresses to the nation, was also being closely watched for the president’s vigor and mental acuity in the wake of Thursday’s debate.
Mr. Biden’s family and his top aides, along with high-profile allies on Capitol Hill and in governor’s mansions, closed ranks over the weekend, insisting that the debate was a one-day aberration that should not keep the president from running a vigorous re-election campaign.
Top campaign aides, in the campaign’s most formal outreach yet to its wealthiest supporters, tried on Monday to tamp down the panic that had captured his financial base. The senior Biden officials downplayed the fallout of the debate despite concerns among donors worried about the future of the campaign.
