Amid this crisis, Air Force One banked out of a crystalline blue sky and landed in what boosters have long described as “America’s desert oasis.” Having already exercised for nearly an hour in the gym of the InterContinental Hotel in San Francisco, the president — wearing a striped shirt with sleeves rolled up, light trousers and brown shoes — jogged down the stairs and posed for pictures with Representative Raul Ruiz and his two infant daughters. He was then driven through blocked streets to Sunnylands, the former Annenberg estate where political leaders and celebrities have come to rest and meet for decades.