I think this is a fair GQ question. Faktshual as possible, plz.
About 45% of Supreme Court cases in the US are either 9-0 or 8-0. Around 60% of cases are either unanimous or with at most two dissenters. Of course, it’s actually a bimodal distribution: after the most common result being unanimous, the second-most-common result is a 5-4 split. But it’s easy to understand why the Supremes would split. There is strong reason to take a case if there are strong disagreements about what the result should be.
But why so many unanimous results, or nearly unanimous results?
If the law is fairly clear for so many cases at the SCOTUS level, then why wasn’t the case similarly clear at lower levels? Why aren’t the majority of clear cases weeded out at lower levels? How exactly does it happen that a majority of cases decided by the court have such a strong consensus? My best guess right now is: there are clear cases of law that most every legal scholar agrees on, but the legal system still benefits from those clear cases occasionally being reinforced with a strong signal at the highest level, to give an imprimatur to the decision that clarifies and standardizes good law across all jurisdictions. There might also be accidental inconsistencies across circuits that deserve a good ironing out every once in a while. Maybe.
My next best guess is that there are simply a large number of fuck-ups at lower levels, and the circuit courts simply don’t catch all of them. The Supremes are a last, and very necessarily, filter for those fuck-ups. I don’t have any other hypothesis right now. Curious about the truth.
So what’s up with Supreme Court unanimity?