Legal Question in Constitutional Law in California

If the US Supreme Court takes either or neither but splits 4-4 in a similar case, all the lower court decisions would stand but would be limited as precedent to the districts where the decision was rendered. The court will eventually muster a majority decision in the area.

The Supreme Court will probably review only one of the numerous "Obamacare" cases. First, though, those decisions will be reviewed by intermediate federal appellate courts. The Supreme Court has the authority to bypass the appellate courts and take the cases directly, but that is unlikely to happen.

If the Supreme Court's decision is 4-4, then the appellate decision it reviewed will stand. But that decision will only control within the jurisdiction of the particular appellate court. It will not be binding on the rest of the country.

Note that most Supreme Court cases are complex. Even in an ostensibly 4-4 decision, there are often issues on which five or more justices agree. When that happens, the decision on those issues is binding nationwide. "Obamacare" has many provisions, and it is relatively unlikely that the Supreme Court will split 4-4 on each and every provision it is asked to review.