Texas Gov. Greg Abbott on Wednesday signed into law a bill that bans abortion the moment a fetal heartbeat has been detected, a move that makes Texas the largest state in the nation to outlaw abortion so early in a pregnancy.

The Texas law effectively prohibits any abortion after around six weeks of pregnancy, before many women are even aware that they are pregnant.

The bill, which takes effect in September, makes no exception for pregnancies that are the result of rape or incest, but does include a rare provision that allows individual citizens to sue anyone they believe may have been involved in helping a pregnant individual violate the ban. The provision cannot be used against pregnant people, but reproductive rights advocates warn it can be used to target abortion providers and abortion-rights activists.

In a letter to lawmakers last month, a coalition of more than 300 Texas attorneys raised constitutional concerns about the language of the legislation, saying the civil lawsuit provision "weaponizes the judicial system," and warning it could subject Texans to harassment and abuse through the legal system.

During a signing ceremony with anti-abortion activists, Gov. Abbott, a Republican, cheered the bill, saying, "Our creator endowed us with the right to life and yet millions of children lose their right to life every year because of abortion."

"In Texas, we work to save those lives," Abbott said. "And that's exactly what the Texas legislature did this session."

The new law adds Texas to a growing list of states with conservative leaders that have passed increasingly restrictive abortion restrictions as part of an effort to challenge the Supreme Court's 1973 Roe v. Wade decision and other U.S. Supreme Court precedent guaranteeing the right to an abortion.

The latest development on that front came Monday, when the court said it would consider a Mississippi law that bans most abortions after 15 weeks — before what is known as fetal viability. The court has previously said that states cannot impose an "undue burden" on a woman's right to an abortion prior to viability.

But with the death of Justice Ruth Bader Ginsburg last year and the confirmation of Justice Amy Coney Barrett, conservatives now hold a 6-3 majority on the court and have begun signaling new willingness to reconsider past precedent.

If the court rules to let the Mississippi law stand, abortion rights supporters fear, it could create a foundation for even more restrictive measures, including the law in Texas, to stand.

In a statement, Texas Right to Life praised the new law as a "landmark victory" and a "vital step in the road to abolishing all abortions in Texas."

Planned Parenthood Texas Votes and the Planned Parenthood Action Fund released a statement condemning the law as "dangerous," and among the "harshest abortion bans in the country."

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