There's a story Americans have learned about the Supreme Court, a story that affects the way we view high-profile cases like the ones about same-sex marriage that it heard last week.

In this story, the Supreme Court has played a crucial, maybe the crucial, role in our country's progress toward ever greater freedom and justice. Brown v. Board of Education — the 1954 decision that outlawed separate-but-equal public schools — is central to that story, the shining example of how the court has broadened our constitutional guarantees.

For many people, a decision in which the court finds a constitutional right to same-sex marriage would be the next great chapter in that book. The story is, however, false. In our actual history, the court has often been a bystander as freedom and equality have grown — and has frequently been a villain.