Toobin explained:

This is a peculiar situation designed to create legal complications. It is not the state of Texas that enforces the law the way it works in most states — the way it works in most states, the way it works in every state — it’s the system of private enforcement, ‘private attorneys general’ it’s called, and what this difficulty it’s created is that it’s unclear who the abortion provider should sue. Usually, you just sue the state government and the court issues an injunction on state government don’t enforce the law. With no single enforcer of the law, there is this procedural problem that abortion providers have that it is unclear who they’re supposed to sue. That’s what’s creating this legal tangle, separate from the issue about the abortion law, but the effect is that this law is now in effect and Roe V. Wade essentially does not exist, at least in the state of Texas and probably more in states to come.