For years now, President Biden's advisers have carefully choreographed his every move to avoid what exploded into view over six hours Thursday: a vivid display of an elderly, irritable man struggling on a public stage.

Why it matters: Days after repeatedly referencing talks with dead world leaders, Biden, 81, went before cameras to bash a just-released special counsel's report that portrayed him as feeble and forgetful — and then confused Egypt's president with Mexico's.

• Biden's hastily arranged nighttime remarks came after the special counsel's report said he wouldn't be charged for having classified documents, but blistered him as "an elderly man with a poor memory" — a political indictment sure to resonate through the 2024 campaign.

Zoom in: After reporters fired questions about the descriptions of his mental state in special counsel Robert Hur's 383-page report, Biden fired back.

• "I'm well-meaning and I'm an elderly man," the president said. "I know what the hell I'm doing. I've been president and I put this country back on its feet. I don't need his recommendation."

With emotion in his voice, Biden noted that special counsel Robert Hur's report had claimed Biden couldn't recall the year his son Beau died of a brain tumor (2015).

• "How in the hell dare he raise that," Biden said. "Frankly, when I was asked the question I thought to myself: 'Wasn't any of their damn business.' "
• Biden insisted "my memory is fine," blamed his staff for the mishandling of classified documents in his home — and referred to President el-Sisi of Egypt as the president of Mexico when talking about the war in Gaza.
• "I think as you know initially, the president of Mexico, Sisi, did not want to open up the gate to humanitarian material to get in," he said.

Between the lines: Thursday's stunning events — Hur's description of Biden in the report, then Biden's shaky press conference — alarmed many senior Democrats, including former aides to Biden.

• Some acknowledged that the report and Biden's appearance afterward could fuel doubts about his chance of being re-elected, and then serving as president until he's 86.
• One House Democrat called Biden's verbal slip-ups "awful," and wondered why the president's staff allowed him to hold a press conference — then field reporters' shouted questions — "that late at night after a full day," instead of Friday morning, when he'd be "fresh."
• Another former Biden White House official simply said: "Brutal."
• Online prediction markets made their own statement: Biden's odds of being the Democratic presidential nominee fell sharply — though he remained the overwhelming favorite.

Zoom out: Many other Democrats were reluctant to say how Hur's report and Biden's reaction to it would impact the presidential race — but said it would be difficult to move to a different nominee.

• A former Biden aide described Democrats' dilemma: "Taking the nomination away from Biden is like taking the car keys away from your parents."
• Others called Hur — a former U.S. attorney who was nominated by then-President Trump — a partisan who was trying to hurt a Democratic president with a medical assessment he wasn't qualified to make.
• "Hur knew exactly what he was doing here," former Obama adviser Stephanie Cutter wrote on X. "He gratuitously leveled a personal (not legal) charge against the president that he absolutely knows is a gift to Trump," the likely GOP nominee for president.

What they're saying: "I think this is survivable because it happened in February," a veteran of past Democratic White Houses said. "If it happened in July, maybe not. They've got to find a way to grapple with this [age] issue more effectively."

• A former Biden administration official agreed: "Voters are concerned about Biden's age, and the only way to dispel those doubts is for Biden to show the voters that he's still got his fastball and aggressively make the case for a second term."

Andrew Solender contributed reporting.