A divided Republican Party descended into turmoil, as a startling chorus of GOP candidates and officials repudiated their own presidential candidate and scrambled to find personal paths to political survival just a month before Election Day.

Republican National Committee Chairman Reince Priebus on Saturday told party officials to redirect funds away from nominee Donald Trump to down-ballot candidates, according to an official informed of the decision. In practical terms, the party will be working to mobilize voters who support...