In a race roiled in recent weeks by scandal, Liban Mohamed, the Muslim son of Somali immigrants, pulled off a surprising upset in a crowded 1st Congressional District, winning the endorsement of a majority of Democratic delegates at the party’s state convention Saturday. Mohamed emerged as the top choice in a field with two candidates — state Sen. Nate Blouin and Salt Lake City Council member Eva Lopez Chavez — stung by scandal in the past two weeks and a front-runner, former U.S. Rep. Ben McAdams, who some delegates viewed as too conservative. After several rounds of ranked-choice voting, McAdams...