A study examined the current United States Supreme Court's treatment of the legal concept of freedom of expression by exploring its decisions and opinions on a quantitative basis. The individual votes and the opinions or legal rationales of the justices were recorded for the 43 First Amendment cases decided by the court between the 1981 appointment of Justice O'Connor and the end of the 1985-86 term. The votes of the justices were recorded in terms of their agreement with each of the other justices, their agreement with the decisions of the courts, and their agreement with outcomes favorable to petitioners claiming violation of their First Amendment rights. Results indicated that the court decided 18 of the 43 cases unanimously, while splitting by one or two votes in 19 cases. Eighteen cases were decided in favor of the litigants claiming violation of First Amendment rights. The court was found to be somewhat more unfavorable than favorable and somewhat more divided than unanimous. Justices Brennan and Marshall were most favorable to First Amendment claimants, and Justices Burger, White, O'Connor and Rehnquist were least favorable. Respective analyses show some differences between how the liberals and conservatives on the Supreme Court vote and how they reason in First Amendment cases. Brennan and Marshall appear to stand resolutely alone in voting, but when they write opinions, White appears to provide at least some leadership in linking some of the conservatives with the liberals. (HTH)