Why is "U.S. state constitutional amendments banning same-sex unions" trending?

Wikipedia Overview

Prior to the Supreme Court's decision in Obergefell v. Hodges (2015), U.S. state constitutional amendments banning same-sex unions of several different types passed, banning legal recognition of same-sex unions in U.S. state constitutions, referred to by proponents as "defense of marriage amendments" or "marriage protection amendments." These state amendments are different from the proposed Federal Marriage Amendment, which would ban same-sex marriage in every U.S. state, and Section 2 of the Defense of Marriage Act, more commonly known as DOMA, which allowed the states not to recognize same-sex marriages from other states. The amendments define marriage as a union between one man and one woman and prevent civil unions or same-sex marriages from being legalized, though some of the amendments bar only the latter. The Obergefell decision in June 2015 invalidated these state constitutional amendments insofar as they prevented same-sex couples from marrying, even though the actual text of these amendments remain written into the state constitutions.