PHOENIX, Ariz.—Incumbent U.S. Sen. Mark Kelly (D-Ariz.) retains a commanding lead over his Republican challenger Blake Masters, despite early polls that showed the race as a toss-up. According to Decision Desk HQ, with 74 percent (1,802,681 ballots) from all precinct votes counted, Kelly leads his opponent, 51.4 percent to 46.4 percent. On Nov. 9, the…