“It is now highly likely that if we eliminate the deadline, Virginia will ratify and become the 38th state, and then the E.R.A. can go into effect as a constitutional amendment,” Mr. Nadler said in an interview Friday. “So it’s time to do it.”

First proposed by women’s suffragists in 1923 and adopted by Congress in 1972, the Equal Rights Amendment, which would bar discrimination on the basis of sex, has for decades been a dream of women’s rights advocates. Its language is simple: “Equality of rights under the law shall not be denied or abridged by the United States or by any state on account of sex.”

Mr. Nadler’s move is part of a string of recent gains for the amendment’s backers, who struggled for years to get politicians of both parties to pay attention to their cause. Five years ago, they founded the E.R.A. Coalition, a nonpartisan umbrella organization for groups that favor seeing the amendment enacted.

Bettina Hager, the coalition’s chief operating officer, said that as recently as 2016, she “was practically begging” for Hillary Clinton, then the Democratic presidential nominee, to talk about the amendment, but the Clinton campaign was unreceptive.

Now, Ms. Hager said, Democratic presidential candidates are not only mentioning the amendment, but competing to embrace it. Without her group’s prompting, Julián Castro raised the issue in a Democratic debate, and Senator Kamala Harris of California and former Vice President Joseph R. Biden Jr. quickly followed suit.