In a candid discussion, Harris acknowledged he used to defend Biden’s mental acuity by separating the president’s communication struggles from his decision-making abilities. “It’s at least intelligible to say, ‘Okay, he’s not a good communicator. He was never a good communicator, he’s only getting worse,’” Harris said. “You can’t reliably stick him in front of a microphone and trust that something good is gonna come out of his mouth.” Harris once accepted the idea that while Biden fumbled public speaking engagements, he was still competent when it came to deliberating important issues in private. “The truth is… when you sit...