It is a contentious issue. The Senate is debating a measure which, if it received a 2/3rds vote in both houses of Congress and then was ratified by 3/4ths of the State legislature, would preserve the definition of marriage as being between a man and a woman. It prevents courts and State legislatures from inventing new definitions of marriage to include other folks.

The reasons to oppose it include a desire to see the definition of marriage expanded, a desire to see marriage become meaningless, and opposition to federalizing the question by Amending the Constitution to include something extraneous to its purpose as a charter of government.

The Reuters wire has an opinion and a headline:

Senate takes up gay-rights ban amid criticism

The Amendment can be considered a number of things, but a “gay-rights ban” is not one of them.