From my understanding, you could have several circuit appeals court decisions stating that it is “constitutional” and it would not make a difference. If just one appeals court rules “unconstitutional” , it is in fact “unconstitutional” since the law errs on the side of “unconstitutional”
If one circuit declares a law unconstitutional...and another circuit declares it constitutional...which is the case with Obamacare...then it is unconstitutional within the geographic bounds of the circuit declaring it so.
And constitutional within the bounds of the other circuit.
Once this awkward circumstance occurs, SCOTUS will take the case and render a decision.