Longtime Biden aide testifies he stood to earn up to $8M had president won re-election

A longtime ally of former President Joe Biden told House Oversight Committee investigators that he could have been paid a total of $8 million if the former president won his 2024 re-election bid, a source familiar with the conversation told Fox News Digital.

Michael Donilon served as senior advisor to the president for the entirety of Biden's four-year term. Their relationship goes back decades, however; Donilon first worked for Biden in 1981 when he was a U.S. senator from Delaware.

He is the latest ex-Biden administration official to sit down with the committee behind closed doors as it investigates whether the former president's inner circle covered up evidence of his alleged mental decline, and if executive actions were signed via autopen without Biden's full awareness.

Donilon said he did not know what the autopen was used for and did not recall having any knowledge of the autopen, the source told Fox News Digital.

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But Donilon, who was the top strategist for Biden's 2020 and 2024 campaigns, would have apparently earned some $8 million total if Biden won.

Donilon told investigators he was paid $4 million to work on Biden's 2024 campaign, the source said. That information was reported by Axios reporter Alex Thompson and CNN host Jake Tapper in their book "Original Sin: President Biden's Decline, Its Cover-up, and His Disastrous Choice to Run Again."

The $4 million he would have gained in addition would have come if Biden had won in 2024.

Biden infamously dropped out of the 2024 race after his disastrous debate against Donald Trump in June of that year, after weeks of mounting pressure by fellow Democrats, both in public and in private.

Donilon told investigators he "believes the punditry and Democrats in Congress overreacted after Joe Biden’s disastrous debate," the source said. Donilon also argued Biden's communications skills "got stronger" during his time as president, the source added.

"During his interview, Mr. Donilon admitted that Joe Biden’s presence wasn’t as commanding, and he could stumble over more words. Mr. Donilon stated he was frustrated and knew it was difficult to get past the visuals of President Biden that people were seeing," the source said.

In his opening statement, obtained by Fox News Digital, Donilon emphasized his 40-year relationship with Biden and touted the Democratic administration's accomplishments through the COVID-19 pandemic, the rebound in job growth in its wake and the Inflation Reduction Act and other legislative wins.

"I was with President Joe Biden from his first day in office to the last day. What I saw, day in and day out, was a leader who was deeply engaged and in command on critical issues, both at home and abroad," Donilon said in his statement.

"Every President ages over the four years of a presidency and President Biden did as well, but he also continued to grow stronger and wiser as a leader as a result of being tested by some of the most difficult challenges any President has ever faced.

"I thought that experience was enormously valuable for the nation. I believed that President Biden was the best person to lead the country on the day he took the oath of office and I continued to believe that was true every day he served as President."

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Donilon is the eighth ex-Biden White House official to appear for the probe led by House Oversight Committee Chairman James Comer, R-Ky.

A source familiar with the Biden team's thinking previously called Republicans' probe "dangerous" and "an attempt to smear and embarrass."

"And their hope is for just one tiny inconsistency between witnesses to appear so that Trump’s DOJ prosecute his political opponents and continue his campaign of revenge," that source said.

Fox News Digital reached out to Donilon's lawyer and a representative for Biden for comment.

Fox News Digital's Deirdre Heavey contributed to this report