WASHINGTON (AP) — (snip) Biden, who has rarely made public appearances since leaving office last year, sat, like many of his fellow passengers, awaiting a flight that would take him to Columbia, South Carolina, for an evening event with the South Carolina Democratic Party. Passengers whispered and gaped in wonder: Why would a man who for a time was leader of the free world be, like they were, at the mercy of airport travel delays, even as he sat ensconced in his security detail? (snip) Biden — seated in the third row of the tiny first class cabin on the...