Former White House press secretary Karine Jean-Pierre is appearing before the House Oversight Committee on Friday for a high-profile interview on whether senior staffers worked to obscure signs of mental decline in then-President Joe Biden.Jean-Pierre is one of the highest-profile figures so far to appear before the committee, having been the most public-facing spokesperson for Biden from May 2022 until the end of his term.The longtime Democrat-turned-Independent did not speak to reporters on her way into her closed-door transcribed interview with House investigators, which is scheduled to begin at 10 a.m. and is likely to last into the afternoon.House Oversight Committee Chair James Comer, R-Ky., is investigating whether there was a cover-up of Biden's mental and physical state in the White House, and whether any executive actions were approved via autopen without the then-president's full awareness.LONGTIME BIDEN AIDE SAYS HE STOOD TO EARN UP TO $8M HAD PRESIDENT WON RE-ELECTIONOf particular interest to committee investigators are the myriad clemency orders Biden signed, including about 2,500 toward the end of his presidency that were executed via autopen.Biden himself told The New York Times recently that he made every clemency decision on his own. His allies have also blasted the Republican-led probe as a partisan exercise.Jean-Pierre was among those who publicly defended Biden in the wake of his disastrous June 2024 debate against then-candidate Donald Trump. She told reporters at a press briefing in early July that Biden was "as sharp as ever."But unlike other ex-Biden administration aides who have appeared ahead of her many of whom still hold close ties and fierce loyalty to Biden Jean-Pierre had a very public falling out with their world earlier this year.In June, Jean-Pierre announced she was writing a book titled "Independent: A Look Inside a Broken White House, Outside the Party Lines."She also announced she was leaving the Democratic Party in a press release for that book, expected in October 2025.A summary for her book suggests it is about "the three weeks that led to Bidens abandonment of his bid for a second term and the betrayal by the Democratic Party that led to his decision."The announcement was reportedly met with scorn by others in Biden's orbit."The hubris of thinking you can position yourself as an outsider when you not only have enjoyed the perks of extreme proximity to power which...bestows the name recognition needed to sell books off your name but have actively wielded it from the biggest pulpit there is, is as breathtaking as it is desperate," one former official told Axios.RON KLAIN DODGES REPORTERS AFTER MARATHON GRILLING IN BIDEN COVER-UP PROBEAnother person told the outlet she "was one of the most ineffectual and unprepared people I've ever worked with."Comer sent a letter to Jean-Pierre in late June asking her to appear for an interview, in which he pointed out she was "a trusted inner-circle confidante" and "near the president daily.""Your assertion, on multiple occasions, that President Bidens decline was attributable to such tactics as cheap fakes or misinformation cannot go without investigation. If White House staff carried out a strategy lasting months or even years to hide the chief executives condition or to perform his duties Congress may need to consider a legislative response," Comer wrote.