Two-thirds of Americans say the use of marijuana should be legal, reflecting a steady increase over the past decade, according to a new Pew Research Center survey. The share of U.S. adults who oppose legalization has fallen from 52% in 2010 to 32% today. Meanwhile, an overwhelming majority of U.S. adults (91%) say marijuana should be legal either for medical and recreational use (59%) or that it should be legal just for medical use (32%). Fewer than one-in-ten (8%) prefer to keep marijuana illegal in all circumstances, according to the survey, conducted Sept. 3 to 15 on Pew Research Center’s...