David Axelrod criticized Robert Mueller on Wednesday, saying the former special counsel was not as “sharp” as he used to be.

Axelrod, who served as chief strategist on both of President Barack Obama’s presidential campaigns, made the comments as Mueller was testifying in front of the House Judiciary Committee about his investigation into Russia’s interference in the 2016 election.

“This is delicate to say, but Mueller, whom I deeply respect, has not publicly testified before Congress in at least six years,” the former Obama adviser said on social media. “And he does not appear as sharp as he was then.”

This is delicate to say, but Mueller, whom I deeply respect, has not publicly testified before Congress in at least six years. And he does not appear as sharp as he was then. — David Axelrod (@davidaxelrod) July 24, 2019

Axelrod followed up his initial tweet by saying Mueller’s performance at the hearing helps explain why he “wanted his aide nearby.”

And it helps explain why Mueller wanted his aide nearby. — David Axelrod (@davidaxelrod) July 24, 2019

On Tuesday, Mueller’s team made a last minute request to the Judiciary Committee that a top long time aide to the former special counsel attend the hearing with him.

Initially, Mueller’s team requested the aide be sworn in and testify alongside the former special counsel. The Judiciary Committee denied the request, but allowed the aide to attend and confer with Mueller as he answered questions.

“Aaron Zebley was the Deputy Special Counsel and had day-to-day oversight of the investigations conducted by the Office,” a Mueller spokesman said in a statement. “He will accompany Special Counsel Mueller to the Wednesday hearings, as was discussed with the committees more than a week ago.”

Despite the help from Zebley, Mueller had difficulty answering questions. Numerous times in his testimony, the former special counsel appeared confused and frail, according to multiple members of the media.

Axelrod, himself, seemed to crack a joke about Mueller’s inability to handle the intense questioning from members of Congress.

“The speed dating approach to questions is hard on Mueller,” Axelrod tweeted.