Donald Trump once questioned the wisdom of taking vacations. “What’s the point?” he asked. But now the president is getting ready to join the annual August exodus from this town he calls “the swamp.” Trump is due to set out Friday on his first extended vacation from Washington since the inauguration — a 17-day getaway to his private golf club in central New Jersey. The president’s vacation could be driven, in part, by necessity. Everyone who works in the White House West Wing, including the Oval Office occupant himself, will be forced to clear out by week’s end so that...