(IF SCOTUS upholds it), towards a potential splitting up of the Union of the States.
If the RW SCOTUS grants foetal personhood (and they can do so without Congress btw), thus outlawing ALL abortions (other than some very very narrow exceptions, and even those may not exist) nationwide, many Blue States will not comply, and thus we reach a massive tipping point.
A Rethug POTUS may well send in federal troops to force the Blue States to comply, kicking off, more than likely, kinetic violence and instant, massive Blue State secessionist movements.
If either a Dem (likely) or a Rethug (unlikely) POTUS refuses to enforce the ruling, the Red States will likely then point to that and say 'fuck you, we are no longer going to comply with rulings WE do not agree with'. Chaos and violence ensues again.
This has, for years, been the path (and there are many subjects that a renegade RW SCOTUS could rule on that could kick it all off) that I most dread in terms of the Union of the States breaking up.
There is no ultimate blocking force for much of the madness IF the SCOTUS puts its stamp of approval on even the most blatantly unconstitutional RW insanity and tyranny, and a Rethug POTUS that agrees with them is in office, especially if they have a Rethug Congress (and even a filibuster-blocked Dem controlled US Senate may not be able to help) backing them.
An extreme scenario to illustrate the ultimate fragility and dependence on good faith that undergirds our US Constitutional form of governance:
Mississippi passes a law making chattel slavery of blacks legal again.
The SCOTUS, despite that being a pure violation of the 13th Amendment (and other parts of the Constitution) says all good, the law is valid. They likely would not, but IF they did, then there is no good solution.
If neither the POTUS nor the Congress does anything to stop Mississippi, then potential (partial or total, depending on the law passed in MS) reenslavement starts. Chaos and violence ensues.
Even if we had a Dem POTUS, they would have to go against the SCOTUS ruling to send in federal troops to stop it, thus shattering the system of checks and balances, destroying the division of power, and thus likely kicking off a massive wave of Red States ignoring previous rulings that they disagree with, and also a possible rise of secessionist movements, along with systemic kinetic violence.
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