Despite a tense recent phone call with President Trump — first reported by the New York Times — the most important mega-donor in the Republican Party, Sheldon Adelson, has signaled he is poised to spend big to support the president. Behind the scenes: Last Monday morning a group of top Republican Party donors gathered at the Four Seasons resort in Jackson Hole, Wyo., for a Trump campaign fundraiser. The donors gathered in a hotel ballroom, set up like a Silicon Valley retreat, with a yogurt parfait station, according to sources in the room. A select few of the party's biggest...