WASHINGTON — Alaska Republican Sen. Lisa Murkowski testified in support of the Equal Rights Amendment at a Senate hearing this week, opposite a fellow Republican senator who opposes it.

The Equal Rights Amendment, which was proposed in Congress in 1972, would codify equal rights for women in the U.S. Constitution and ban discrimination based on sex. Along with Sen. Ben Cardin, a Maryland Democrat, Murkowski sponsored legislation in the Senate in January that would remove the deadline to ratify the Equal Rights Amendment and recognizes that three-quarters of states have ratified the amendm...