The local cop who interrupted Thomas Crooks’ assassination attempt on Donald Trump — but failed to stop the deranged gunman from squeezing the trigger — saved the ex-president’s life, a Pennsylvania sheriff insisted Tuesday. Butler County Sheriff Michael Slupe doubled down on his defense of the Butler Township police officer who confronted Crooks at the Saturday rally and assailed online critics as “a–holes” in an interview with The Post. Slupe argued that the officer — whose department was enlisted by the Secret Service to help during the rally — merely coming face to face with the shooter delayed what could...