The national field director for Donald J. Trump’s campaign — who is a loyalist to Corey Lewandowski, the embattled campaign manager — resigned in a letter to Mr. Trump on Monday afternoon. “I want to express my deepest gratitude for the opportunity to serve you and your campaign over the past 7 months,” Stuart Jolly, the director, wrote in his resignation letter. “The journey has been extraordinary and many experiences on this journey will never be forgotten.” Mr. Jolly, a retired Army lieutenant colonel, was especially loyal to Mr. Lewandowski, whom he had worked with previously at Americans For Prosperity,...
