Nearly two-thirds of Americans say smoking marijuana is “morally acceptable,” while 31 percent disapprove of pot on moral grounds, according to a survey released Monday by Gallup. That’s a sharp jump from 2013, when a similarly worded question in a Public Religion Research Institute survey found that slightly fewer than half of Americans said it was morally acceptable to smoke marijuana. The shift in moral acceptance of marijuana mirrors the shift in support for legalization over that time period, which rose from 48 percent at the end of 2012 to 64 percent last fall, according to Gallup. On the spectrum of morality, Americans now rate marijuana use similarly to gay and lesbian relations, stem cell research or having a baby outside of marriage, according to Gallup.