PORTLAND, OR — In a stunning turn of events, downtown Portland’s decades-long struggle with open-air drug use has officially ended—thanks to a bold new policy initiative: putting up a lot of signs. Lining the street like hopeful little soldiers, a series of “DRUG-FREE ZONE” signs now boldly mark what was, until this week, a fentanyl enthusiast’s paradise. Each sign features a red circle crossing out a syringe, accompanied by stern Helvetica lettering reminding passersby that drugs are now...