The legalization of same-sex marriage is a potent example of a dominant theme in American history: Over time, civil rights expand, and discrimination ebbs. …
As a result, it’s fair to divide the major issues in American political life into two broad categories. In one category are the rights-based issues in which the future can be safely predicted. In the other category — which includes abortion, gun control and climate change — there is far less clarity about the direction of public opinion. CONT.
David Leonhardt & Alicia Parlapiano, New York Times