Ex-White House spokesman Andrew Bates is appearing on Capitol Hill Friday morning as the House Oversight Committee continues its probe into allegations of a cover-up by former President Joe Bidens inner circle.Bates was a core member of Biden's communications team for nearly his entire four-year term, rising from deputy to senior deputy press secretary by the time the Democratic leader left office in January 2025.Hes the 11th former Biden official to appear for the House Oversight Committees probe and the ninth to do so voluntarily.LONGTIME BIDEN AIDE SAYS HE STOOD TO EARN UP TO $8M HAD PRESIDENT WON RE-ELECTIONThree ex-Biden aides Anthony Bernal, Annie Tomasini, and ex-White House physician Kevin OConnor were compelled to appear via congressional subpoena.House Oversight Committee Chair James Comer, R-Ky., has been investigating whether Bidens senior aides covered up signs of mental decline in the former president, and whether any executive decisions were signed off on via autopen without the then-leaders full awareness.Theyre looking in particular at the litany of clemency orders that Biden signed in the latter half of his term."You served as Senior Deputy Press Secretary in the White House during former President Joe Bidens Administration. You also served in communications roles during the 2020 Biden campaign and during the Obama-Biden Administration. Other than Karine Jean-Pierre, you were one of the most prominent public-facing defenders of former President Bidens mental acuity," Comer wrote to Bates in late June."The scope of your responsibilitiesboth official and otherwiseand personal interactions within the Oval Office cannot go without investigation, given the mounting evidence that President Biden was incapacitated for much, if not all, of his single term," the letter continued.Democrats, by contrast, have painted the investigation as an unnecessary look backwards.Comer had previously described the Democratic sides questioning of Biden witnesses as trivial, accusing them of spending little to no time trying to glean any meaningful information.RON KLAIN DODGES REPORTERS AFTER MARATHON GRILLING IN BIDEN COVER-UP PROBEHe said after the interview of another Biden spokesman, Ian Sams, "The Democrats' questioningmay have lasted three minutes. They let him read an opening statement, and they did their basic: what's your favorite color? And who's your favorite cartoon character?"Rep. Robert Garcia, D-Calif., the top Democrat on the committee, said ahead of Bates' interview on Thursday, "I think the important thing about that investigation is Republicans, surely on the Oversight committee, they seem obsessed with the healthcare of Joe Biden and Joe Biden's health.""They should be putting their efforts and focus on the healthcare of the American public, versus obsessing about Joe Biden and what he did, he didn't do. That's in the past, we're trying to move forward," Garcia said.