PARIS — President Donald Trump’s decision to cancel his visit to an American military cemetery outside of Paris threatened to overshadow his trip here, as government officials, historians and fellow Republicans hammered him for more than 24 hours for that move. “President@realDonaldTrump a no-show because of raindrops? Those veterans the president didn’t bother to honor fought in the rain, in the mud, in the snow — & many died in trenches for the cause of freedom. Rain didn’t stop them & it shouldn’t have stopped an American president,” wrote former Secretary of State John Kerry, a veteran of the Vietnam...