In a highly anticipated ABC interview, President Joe Biden firmly rejected calls for an independent medical evaluation that would demonstrate his fitness to serve another term in office. Facing growing concerns within his own party about his capacity to lead, the 81-year-old Democrat insisted that he undergoes regular cognitive assessments and remains in good health, despite his shaky debate performance against former President Donald Trump. As Biden fights to salvage his endangered reelection bid, the interview was seen as a crucial test of his ability to convince voters that he is up for the…