Answer:
A lawyer who is interested in understanding why most justices ruled in a particular way in a Supreme court case should consult the case's majority opinion.
Step-by-step explanation:
In law, the majority opinion is a judicial opinion that has been agreed on by more than half of the members of a court. The majority opinion sets out the court's judgment and reasoning. The justice who authors the majority opinion summarizes the opinion of the rest of the justices during the session of the court. There are some occasions in which the court's justices don't get a majority consensus and cannot agree on the same set of reasons, in those cases a majority opinion is not issued but several concurring opinions may be written.
If a lawyer wants to understand the thought process behind the Supreme Court's rulling, the lawyer should read different majority opinions to find out the justice's reasoning for each specific case.