PORTLAND, OR — In what company executives are calling their “most ambitious expansion yet,” Spirit Halloween announced Tuesday that it will seize the opportunity presented by Portland’s vacant downtown to convert every empty storefront into a seasonal costume superstore by October. “Frankly, it just made sense,” said Spirit CEO Craig Phillips, adjusting a rubber Michael Myers mask during a press conference held in the hollowed-out husk of what used to be a Whole Foods. “We saw boarded-up...