Dr. Mehmet Oz has seen enough, and he isn’t waiting for a recount. Sitting on a 910-vote lead in preliminary, unofficial tallies from Pennsylvania’s Republican Senate primary race as of Friday morning, Oz declared himself the presumptive winner in a new video release in which he took a definitive turn toward a general election campaign between two unorthodox candidates who rocketed to personal fame in wildly different ways. That race to come, for a Senate seat currently held by Republican Pat Toomey, who did not seek re-election this year, is also one of a handful that will be pivotal in...