Nikki Haley is not as loud or fiery as some of her pulpit-pounding rivals for the Republican presidential nomination. But her pleas for common sense and experience in the White House often leave crowds wanting more.
Ms. Haley, 51, the former South Carolina governor and United Nations ambassador, has been on the campaign trail in Iowa and New Hampshire as she seeks to challenge Donald J. Trump, the front-runner.
Her stump speeches often stick to…