PHOENIX — Arizona delegates to the Republican National Convention gathered this month in a Phoenix suburb, showing up to get to know each other and learn about their duties.Part of the presentation included a secret plan to throw the party’s nomination of Donald Trump for president into chaos.The instructions did not come from “Never Trumpers” hoping to stop the party from nominating a felon when delegates gather in Milwaukee next month. They instead came from avowed “America First” believers hatching a challenge from the far right — a plot to release the delegates from their pledge to support Trump, according...