One week ahead of CNN’s debate between former President Donald Trump and President Joe Biden, the MAGA hopeful admitted that he isn’t “underestimating” the president, despite taking aim at his mental acuity for months. POLITICO national political correspondent Meredith McGraw wrote via X (formerly Twitter), “Trump to @theallinpod on upcoming debate against Biden: ‘All I can say is this, I watched him with [former US Rep.] Paul Ryan (R-OH) and he destroyed Paul Ryan. Paul Ryan with the water, he was chugging water left and right…and he beat Paul Ryan. So I’m not underestimating him.'” McGraw …