This resolution would amend the Constitution to define marriage as a union only between a man and a woman.
Passed in 1996, the Defense of Marriage Act (DOMA) allowed states to not acknowledge same-sex unions officiated in other states that don't limit marriage to heterosexual unions. In 2013's United States v. Windsor, the Supreme Court ruled that the previous federal ban on same-sex marriage was unconstitutional due to the “Equal Protection Clause” in the Constitution.
This amendment would nullify the U.S. v. Windsor ruling, by mandating that "neither this Constitution, nor the constitution of any State," be required to bestow marriage benefits on any same-sex couple.
A case heard by the Supreme Court in April 2015 — Obergefell v. Hodges — dealt with whether the Equal Protection Clause requires states to provide marriage licenses to same-sex couples, and whether they must recognize same-sex marriages performed out-of-state. In a 5 to 4 ruling, the Supreme Court effectively legalized same-sex marriage nationwide. The only recourse remaining to those opposing same-sex marriages would be a constitutional amendment such as this or other proposals.