Joe Biden says he has a strict rule about his phone: No matter what's happening, he always answers a call from one of his grandchildren. Biden said on the campaign trail that he kept up with them every day of the pandemic with calls and texts, and now the ritual has carried over to his life in the White House. He checks in on his grandchildren with almost religious devotion, often reaching out multiple times a week, according to two people familiar with the first family's habits. "No topic is off limits," one of them said, even if "sometimes the...