Since the early 2000s, we’ve seen opposition to same-sex marriage and legal marijuana use drop by around 25 percentage points. Public opinion on abortion, however, has been less fluid. In 2000, 53 percent thought abortion should be legal in all or most cases, while 43 percent thought it should be illegal in all or most cases. In 2017, support for legalized abortion had ticked up to 57 percent, and opposition had ticked down to 40 percent. Those numbers reflect gradual shifts, far from the seismic changes we’ve seen on other cultural issues.