And "circuit" in the US is about region, not hierarchy. California has a hierarchy of federal courts and as 9th circuit, they are allowed to rule differently fr

And "circuit" in the US is about region, not hierarchy. California has a hierarchy of federal courts and as 9th circuit, they are allowed to rule differently from the hierarchies of federal courts in Texas (in the 5th circuit) or Colorado (in the 10th). They don't have to but they can. At some point, if the US Supreme Court steps in (which they don't have to), one reasoning gets picked (or yet another one cooked up) which then stands for all regions and the courts are then strongly dissuaded from screwing with it any further.