Editor
Former President Donald J. Trump capped off a clean sweep of Republican delegates in Michigan on Saturday during a raucous convention, which further exposed a deep fissure in the state party that threatens to fester in one of the most important battleground states.
Mr. Trump, the Republican front-runner, amassed at least 90 percent of the vote in all but one of the state’s 13 congressional districts against former Gov. Nikki Haley of South…
