IF the goal is to get a case before SCOTUS on the issue of when there is a compelling gov't interest in banning abortion, why all the nonsense with citizens suing others? Had they just passed a law banning abortion at 6 week because there was a compelling interest with fetal heartbeats, wouldn't they have gotten to SCOTUS just as much?
If they passed an outright ban, there are many people and groups who could goo into a Texas court and have it tossed out based on Roe v. Wade. There have been similar laws and cases that have been lost in lower courts where the Supreme Court has refused to hear the case. Roberts in particular has basically said he is not interested in reversing or even revisiting Roe V. Wade. Such a case probably wouldn't make it to the Supreme Court.
By making this a civil action, it is not just a redo of Roe v. Wade. It is a different type of case that they hope will make it to the Supreme Court. A civil action also means the law is not subject to the same constitutional standard if it were a government action. Sort of.
The civil action also puts the people providing the abortion of the defensive. With a ban, practically anybody could sue the government and the government would be the . With this law, a person providing abortions becomes the defendant. If doctors are afraid of being sued, they have already accomplished their goal. If not, a well financed anti-abortion group can sue some doctor.
A government action like a ban has to be in compliance with both the Texas and U.S. Constitutions which place a number of limitations on government. Those limitation do not necessarily apply to private civil actions.
The legislature can dictate who has standing and what constitute allowable defenses. There are existing similar laws. For example, a law may say someone can sue somebody for something and that intoxication is not an allowable defense. This law prohibits a defense based on "a defendant's belief that the requirements of this subchapter are unconstitutional or were unconstitutional". That would not be allowed for a government action. For a civil action...that's bizarre enough that the Supreme Court may hear that case.
It also prohibits "a defendant's reliance on any state or federal court decision that is not binding on the court in which the action has been brought". What court decisions are not binding? Well, they put that in too: "A defendant against whom an action is brought...does not have standing to assert the rights of women seeking an abortion as a defense to liability...unless...the United States Supreme Court holds that the courts of this state must confer standing..."
The Supreme Court ruled that a woman is entitled to an abortion. But this law does not prohibit a woman from getting an abortion. It doesn't even prohibit it indirectly by banning people from performing an abortion. This is just a civil action against an abortion provider. The Supreme Court hasn't ruled that people have a constitutional right to perform an abortion. And this law says that an abortion provider can't use Roe v. Wade as a defense because that would not be a binding court decision.
That is, unless the Supreme Court rules otherwise. By making a civil action, is skirts around outside Roe v. Wade. It says this is a different independent matter. And Roe v. Wade can't come into it unless the Supreme Court says otherwise.
That sets it up so that the Texas courts have to go along with this law and the only way to rely on Roe v. Wade is to take it to the Supreme Court. Because it is such a strange case, the Supreme Court would pretty much have to hear the case. That's when they try to get a opinion that there is a government interest in allowing abortion providers to be sued, which is a new sperate issue that would not actually be a reversal of Roe v. Wade.