A question about the US Supreme Court and how they decide

what do you think

Do you think Supreme Court Justices first decide what they want the outcome to be ….and then come up with a justification for what they want and write their justification in their written decision?

Or do you think it is a genuine application of the law and the Constitution that leads them to a particular conclusion and then they write an opinion explaining?

Or do you have another thought about this?