The state of the union as President Biden appeared before a divided Congress on Thursday night was rowdy.
Mr. Biden delivered a feisty, shouty, confrontational speech. Republicans jeered when he challenged them on immigration and economic matters, and he appeared to relish and even encourage the unscripted back and forth as he made his formal address on Capitol Hill.
Democrats cheered loudly and often in support of his policies, giving the impression of a party fully behind — and even excited about — its aged presidential nominee. The only glimmers of Democratic dissent came from a few progressives who sat stone-faced and held up signs demanding a lasting cease-fire between Israel and Hamas during portions of the speech.
It all unfolded as former Representative George Santos of New York, the serial fabulist who was expelled from Congress by his own colleagues in December, made a splashy return to the House floor that he had vowed only months ago to never visit again. Mr. Santos, dressed in a crystal-encrusted collar and sparkling shoes, even made his own news during Mr. Biden’s speech. He announced on social media that he planned to make another run for Congress, this time from New York’s First Congressional District.
It was, in short, a raucous night for a typically staid Washington tradition.
Speaker Mike Johnson, presiding over his first State of the Union since his improbable elevation last fall, could not seem to decide what to do with his face, alternating between pursing his lips, smiling, frowning, arching his eyebrows and shaking his head ruefully as the president spoke.
Some Republicans sat in the chamber looking and acting as if they were attending a rally for former President Donald J. Trump rather than a joint session of Congress. Representative Troy Nehls, the Texas Republican who earlier this year floated the idea of electing Mr. Trump as speaker, came wearing a T-shirt decorated with Mr. Trump’s mug shot.
As he made his way to the rostrum, Mr. Biden gasped and appeared taken aback by Representative Marjorie Taylor Greene, the hard-right Republican from Georgia, who had dressed herself as a one-woman political protest. She wore a red “Make America Great Again” cap and a T-shirt emblazoned with the name of Laken Riley, the 22-year-old nursing student allegedly killed by a Venezuelan migrant, a horror story Republicans have used as a cudgel against Mr. Biden.
“It’s about Laken Riley!” she cried out later from her seat during the segment of Mr. Biden’s speech devoted to the U.S. border with Mexico, in which Mr. Biden blamed his “predecessor” (as he referred to Mr. Trump all night) for tanking a bipartisan border security bill.
Ms. Greene saw her moment, interrupting the president to call the suspect in Ms. Riley’s killing an “illegal.” The authorities have charged a Venezuelan migrant who crossed into the United States illegally and was then released on parole. “Say her name!” Ms. Greene shouted.
In response, Mr. Biden did, in fact, say her name, albeit botching the pronunciation so it sounded more like “Lincoln Riley.” The president referred to her as “an innocent young woman who was killed by an illegal — that’s right.”
“But how many of thousands of people are being killed by legals?” he said.
(For years, studies have found that undocumented immigrants have much lower crime rates than citizens born in the United States and legal immigrants across a variety of offenses, including violent crimes, drug crimes and property crimes.)
He added: “To her parents, I say, my heart goes out to you. Having lost children myself, I understand.”
The president’s off-script use of the term “illegal” drew immediate pushback from progressives. “No human being is illegal,” Representative Delia Ramirez, Democrat of Illinois, posted on social media shortly after he uttered the word.
Still, the jousting with Republican critics appeared to energize Mr. Biden and the Democrats sitting in the audience.
From their chants of “four more years!” as Mr. Biden made his way into the chamber, to the constant exclamations of “that’s right!” that punctuated his speech, Democrats were quick to their feet for applause lines and cheered wildly for the leader of their party.
There were a few exceptions. Representatives Rashida Tlaib of Michigan, Cori Bush of Missouri and Ayanna Pressley of Massachusetts held up signs that said “lasting cease-fire now” and “stop sending bombs” while Mr. Biden discussed the war in Israel.
“More than 30,000 Palestinians have been killed, most of whom are not Hamas,” he said. “Thousands and thousands of innocents, women and children. Girls and boys also orphaned. Nearly two million more Palestinians under bombardment or displacement.”
As Mr. Biden ticked through the wreckage in Gaza, Ms. Tlaib, the only Palestinian-born member of Congress, wiped tears from her eyes and was comforted by her colleagues.
On the other side of the chamber, Mr. Santos was greeted more warmly than he ever had been when he was a member of Congress, back when his colleagues wanted nothing to do with him. Before the speech, he sat and chuckled with Representatives Lauren Boebert of Colorado and Matt Gaetz of Florida. Even members who had publicly criticized him in the past, like Representative Claudia Tenney of New York, stopped to snap his picture, while others made a beeline to greet him.
It was fair to say that Mr. Santos, who is scheduled to go on trial in September on federal fraud charges that include accusations of stealing money from campaign donors for personal expenses, was holding court.
He appeared to be staking out a seat near the corridor where Mr. Biden was set to enter the chamber, positioning himself to be close enough to reach out for a presidential handshake. But minutes before Mr. Biden’s entrance, without a seat saved, Mr. Santos moved himself to the back and out of sight.
It was Mr. Biden who stayed in sight until the bitter end. Long after he had finished speaking, and after most lawmakers, cabinet secretaries and Supreme Court justices had cleared out of the chamber, the president closed down the joint, sticking around with a few stragglers to shake hands and chat for close to 30 minutes more.
“You fired us all up!” Representative Danny K. Davis, Democrat of Illinois, told him.
