I think the way this will works out is that the
Taney Roberts Court renders decisions that allow states to opt out of the ACA and out of any constitutional requirement to acknowledge gay marriages made in other states. This "states rights" view is a plunge into antebellum law, and the conservative justices will probably have to revive pre-Civil War precedents to justify it; they may also revive the legal basis for racial segregation in doing so.
In the long term, I cannot imagine how the USA can survive with an early 19th-cenutry legal system. The antebellum system dissolved into civil war; I do not think the republic will fare any better under the legal regime the Roberts Court is creating.