COLUMBUS, Ohio (AP) — An anti-abortion group fell short Tuesday in its attempt to gather enough signatures to ask voters this fall to change the state constitution to declare that life begins when a human egg is fertilized.

Backers of the proposed constitutional amendment in Ohio, a key state in the upcoming presidential election, and elsewhere hope to spark a legal challenge to the U.S. Supreme Court’s landmark 1973 Roe v. Wade decision, which upheld a woman’s right to an abortion until the fetus is viable outside the womb, usually at 22 to 24 weeks.