<P> Former Justice Scalia professed frustration that there is little substantive discussion, while former Chief Justice Rehnquist wrote that this makes the conference more efficient . The votes are tallied, and the responsibility for writing the opinion in the case is assigned to one of the justices; the most senior Justice voting in the majority (but always the Chief Justice if he is in the majority) makes the assignment, and can assign the responsibility to him - or herself . </P> <P> The justice writing the opinion for the court will produce and circulate a draft opinion to the other justices . Each justice's law clerks may be involved in this phase . In modern Supreme Court history only a few justices, such as former Justice Antonin Scalia, have regularly written their own first drafts . Once the draft opinion has been reviewed, the remaining Justices may recommend changes to the opinion . Whether these changes are accommodated depends on the legal philosophy of the drafters as well as on how strong a majority the opinion garnered at conference . A justice may instead simply join the opinion at that point without comment . </P> <P> Votes at conference are preliminary; while opinions are being circulated, it is not unheard of for a justice to change sides . A justice may be swayed by the persuasiveness (or lack thereof) of the opinion or dissent, or as a result of reflection and discussion on the points of law at issue . </P> <P> The evolution of the justices' views during the circulation of draft opinions can change the outcome of the case; an opinion that begins as a majority opinion can become a dissenting opinion, and vice versa . At the conference for Planned Parenthood v. Casey, Justice Kennedy is said to have initially voted with Chief Justice Rehnquist, but then changed his mind, feeling unable to join Rehnquist's draft opinion . While working for the Justice Department, present - day Chief Justice John Roberts--a former Rehnquist law clerk--wrote an analysis of Wallace v. Jaffree in which he indicated his belief (based on the length and structure) that Rehnquist's dissent had started out as an opinion for the court, but lost its majority; similar speculation is often heard of Justice O'Connor's dissent in Kelo v. New London . Justice Kennedy is known within the Court for changing his mind subsequent to the conference, and Justice Thomas is known for having the tendency to lose a majority . Justices may change sides at any time prior to the handing down of the Court's opinion . Generally, the Court's decision is the opinion which a majority (five or more) of justices have joined . In rare instances, the Court will issue a plurality opinion in which four or fewer Justices agree on one opinion, but the others are so fractured that they cannot agree on a position . In this circumstance, in order to determine what the decision is lawyers and judges will analyze the opinions to determine on which points a majority agrees . An example of a case decided by a plurality opinion is Hamdi v. Rumsfeld . </P>

How does the supreme court decide which cases to hear explain two factors