Here’s the latest on the hearing.

Robert K. Hur, the special counsel whose investigation of President Biden’s handling of classified documents raised questions about the president’s mental acuity, defended his inclusion of the disparaging remarks on Tuesday during a hearing before the House Judiciary Committee.

In February, Mr. Hur concluded a yearlong investigation into Mr. Biden’s retention of sensitive government documents by finding that the president should face no criminal charges. But Mr. Hur, using language Mr. Biden’s team saw as gratuitous, politically damaging and outside his job description, described the octogenarian president as “a sympathetic, well-meaning, elderly man with a poor memory,” likely to be acquitted by any jury.

Mr. Hur, 51, began the hearing as a uniquely unifying figure in divided Washington — a man disdained by Democrats and Republicans alike. He is facing withering questioning from both parties as he explains his assessment of Mr. Biden and the barbed prose in his 345-page report.

He pushed back against criticism of his report, telling the committee that his unflattering description of Mr. Biden was required to “show my work” to justify why he did not charge the president after uncovering some evidence that he had knowingly held onto classified documents. “I could not make that determination without assessing the president’s state of mind,” he said.

The hearing began with the Republican chairman of the committee, Representative Jim Jordan, questioning the fairness of prosecuting former President Donald J. Trump and not Mr. Biden — even though Mr. Hur has said Mr. Trump’s actions were incomparably worse. The opening statements from committee members made clear the hearing would be something of a proxy battle for the coming presidential contest: Republicans played a video of Mr. Biden’s news conference after the Hur report was released, while Democrats played a highlight reel of miscues by Mr. Trump.

Here’s what else to know:

• Republicans are peppering Mr. Hur about his interactions with Justice Department officials and his legal justifications for not charging Mr. Biden, despite finding evidence suggesting that he knew some of the material he possessed was secret. The representatives have also used the hearing to stoke concern about his age and memory.

• Democrats are criticizing Mr. Hur for making broad assertions about Mr. Biden’s memory and trying to undermine his authority to make such an assessment, presenting the report as purposeful, politically motivated and over the top.

• Mr. Hur is testifying as a private citizen, not a Justice Department employee: As of Monday, he had resigned as special counsel and will be represented by a private lawyer, William A. Burck, according to a department spokesman. Mr. Burck, former deputy counsel in the George W. Bush White House, did not immediately respond to a request for comment.

• The political stakes of Tuesday’s hearing, while still high, are on display days after Mr. Biden delivered a fiery defense of his presidency during a State of the Union speech that seemed to address some of the concerns about age and mental fitness raised by the special counsel.

• It is not unusual for witnesses in federal cases to cite their faulty recollections in interviews with investigators, particularly about events that occurred years earlier. But Mr. Hur included references to Mr. Biden’s memory that did not relate directly to retaining classified documents — including the president’s struggle to recall the year (2015) when his son Beau died.