While Republicans on the House Oversight Committee have started questioning former President Joe Biden's Cabinet members about the alleged cover-up of his cognitive decline, a former Democratic National Committee (DNC) insider says she is sitting on a trove of answers. In a wide-ranging exclusive interview with Fox News Digital, Lindy Li, a former DNC fundraiser and National Finance Committee member, detailed her front-row seat to Biden's presidency and the people who pulled the strings behind the scenes. "[Biden is] definitely complicit, but there were a lot of people behind him, like puppet masters. [Former first lady Jill Biden] very much knew what she was doing. What she did was absolutely elder abuse. There is no question in my mind," Li said. Last week, House Committee on Oversight and Government Reform Chairman James Comer, R-Ky., issued a subpoena to Anthony Bernal, former assistant to the president and senior advisor to the first lady, to appear for a July 16 deposition. TOP BIDEN OFFICIALS SUMMONED TO TESTIFY ABOUT ALLEGED COVER-UP OF FORMER PRESIDENT'S MENTAL FITNESS"They deny the cover-up, but I had a front-row seat watching it happen. People like Anthony Bernal. I saw him running the White House like he was in charge, like he was a king. It's just so amazing now to see him dodge a subpoena and completely dodge accountability. He can run, but he can't hide. His name is going to go down in infamy forever," Li told Fox News Digital. WHO IS ANTHONY BERNAL?: THE 'INDISPENSABLE' BIDEN AIDE DITCHING HOUSE OVERSIGHT PROBE ON HIS MENTAL DECLINEBernal had confirmed his appearance for a voluntary transcribed interview before the committee on June 26, but after the White House Counsel’s office informed him it was waiving executive privilege for the Oversight committee’s investigation, he refused to appear. Li said Bernal, who also served as the first lady's chief of staff, "followed Jill around like a dog." While Bernal's apparent power grab coincided with Jill Biden's growing role in the Biden White House, Li added that he ran the East Wing more than the West Wing. Li, who attended events at the White House and organized fundraisers in critical battleground states during the 2024 presidential election, said that in addition to Bernal, deputy chief of staff Bruce Reed, counselor Steve Ricchetti and senior advisors Anita Dunn and Mike Donilon were among those running the White House during Biden's presidency. Fox News Digital reached out to the aforementioned Biden aides but did not receive a response. Biden's former domestic policy advisor, Neera Tanden, testified for hours before the House Oversight Committee last week about her knowledge of the autopen, an automatic signature tool used throughout past presidencies that allowed aides to sign pardons, memos and other important documents on Biden's behalf. Tanden told reporters that she "answered every question, was pleased to discuss my public service, and it was a thorough process," adding she was "glad I answered everyone's question."Li said Tanden played an "intricate" role in using the autopen when "Biden was manifestly unqualified and unable to prosecute the duties of the office."The former DNC insider said Tanden's remarks that she "answered every question" reminded her of Jill Biden's demeanor after her husband's disastrous and consequential debate performance one year ago. Li said she was in the room when Jill proclaimed, "You answered every question!" and said the Democratic Party went to great lengths, even then, to cover up Biden's cognitive decline. She said that included talking points from Biden's campaign managers, who claimed Biden couldn't drop out of the race due to campaign finance laws. "This is such an eerie parallel. It's not enough to just give empty answers," Li said. The former Democrat, who said she has faced the wrath of her former friends and colleagues since she left the party, added that Jill Biden was ultimately the one running the White House. "Joe was not able to do a lot of campaign events, so Jill would come out on his behalf, acting like the president or the presidential candidate. That's why she graced the Vogue cover three times. She loved it. If I were to pinpoint two reasons why Joe decided to run again, it would be two people: Jill and Hunter Biden. Because Hunter Biden's freedom was on the line and Jill's ego was on the line," Li said. Before the president ultimately dropped out of the race and endorsed Vice President Kamala Harris last summer, Jill Biden took a break from the campaign trail to show her support for Hunter Biden at his federal trial. Hunter was found guilty on all counts but received a presidential pardon from his father before departing the White House in January. When reached for comment about her allegations, a former Biden official quipped, "Who is Lindy Li?"Fox News' Danielle Wallace, Alec Schemmel, Elizabeth Elkind and David Spunt contributed to this report.