WASHINGTON — Vacation jaunts and hobnobbing with global elites at a Swiss ski resort are out for President Donald Trump. Visits with troops and farmers are OK. Like some of his recent predecessors, Trump is carefully picking and choosing where he’ll travel during the partial government shutdown. He visited with U.S. troops stationed at a military base in western Iraq the day after Christmas and flew to the U.S.-Mexico border in southern Texas last week to try to buttress his argument for billions of dollars to build a wall to stem illegal immigration, drug trafficking and crime.