PHOENIX -- Proposition 139, which would constitutionally protect the right to an abortion in Arizona, appeared likely to pass after early results were released Tuesday night.

The citizen-led ballot initiative had 63.7% support out of the first 1.7 million votes, according to results posted by the Arizona Secretary of State's Office just after 8 p.m.

Supporters of Prop 139 said it was an issue of women's reproductive rights, while opponents believed it went too far.

The issue has been front and center in the state since Roe v. Wade was overturned two years ago.

In addition to essentially returning the state's abortion law to what it was before the U.S. Supreme Court overruled the landmark 1973 decision, the measure would limit the state's ability to adopt or enforce future laws that would restrict access to the procedure.

The language in the initiative protects the protects the right to an abortion "before the point of fetal viability" and defines fetal viability as "the point of pregnancy when there is significant chance of the survival of the fetus outside of the uterus without the application of extraordinary medical measures."

The current law allows abortions up to 15 weeks of pregnancy. It is the result of legislation passed this year to prevent near-total ban that originated in the Civil War era from going into effect.

The initiative survived multiple legal challenges after supporters gathered more than twice the necessary signatures to put it on the ballot.

Colorado, Florida, Maryland, New York, Nevada and South Dakota also all have abortion-related issues on their ballots this year.