Standing outside the U.S. Supreme Court building as Justice Anthony Kennedy announced a ruling affirming a constitutional right to marriage equality for gays and lesbians in every state across the nation, it was impossible not to feel a part of history. Same-sex couples’ long struggle to have their relationships and families treated equally has been described as the civil-rights issue of our time.

Kennedy’s concluding words were a powerful reminder of Americans’ shared basic humanity: Gay and lesbian couples’ hope, he wrote, “is not to be condemned to live in loneliness, excluded from one of civilization’s oldest institutions. They ask for equal dignity in the eyes of the law. The Constitution grants them that right.”

Punctuating the moment, the Gay Men’s Chorus broke out singing “The Star-Spangled Banner” on the courthouse steps.

One person left out of this historic moment for the Roberts court? Chief Justice John Roberts, who joined three other conservative justices in dissent. Ironically, the case that may define the Roberts court was decided without the chief’s vote.

While it is true that the chief justice has only a single vote, just like every other justice, Roberts’ legacy is inextricably linked with the court’s place in history. When we discuss the Supreme Court, we label it according to the person sitting in the chief’s chair.

The Warren court, led by Chief Justice Earl Warren, for example, decided such landmark cases as Brown v. Board of Education, which held school segregation unconstitutional, and many important criminal justice precedents including Miranda v. Arizona, which instituted the Miranda warnings that protect individuals when confronted by law enforcement. Warren’s legacy would be quite different if the most important cases of the “Warren court” were decided without his vote.

The gist of the reason why Roberts did not join the five-justice majority affirming a constitutional right to marriage equality was that he thought the issue should be resolved through the democratic process, not by judges.

But that’s not the way constitutional rights work. The Constitution enshrines certain rights and liberties that are so important they are placed above the politics of the day. When individuals come in to courts claiming that their constitutional rights have been violated, it is a judge’s duty to vindicate them.

So perhaps the oddest part of Roberts’ dissent is his claim that the Constitution had “nothing to do with” the majority’s vindication of marriage equality. The Constitution had everything to do with why the Supreme Court held that gay and lesbian couples have a right to marry the person of their choosing, and have their families recognized as equal.

In writing into the 14th amendment a requirement of equality under the law and equality of basic rights for all people — which includes the right to marry — the amendment’s framers ensured that discriminatory state laws would not stand in the way of Americans exercising their right to marry the person of their choosing. Laws that discriminate and deny to members of certain groups — including gay men and lesbians — the right to marry the person they choose cannot be squared with the original meaning of the amendment.

The Supreme Court has many times vindicated this principle. Most famously, in the landmark 1967 decision, Loving v. Virginia, the Warren court invalidated the laws of Virginia and 15 other states that outlawed interracial marriage. Friday’s Obergefell v. Hodges ruling on same-sex marriage will stand alongside the Loving decision in history.

In contrast to the sharply divided same-sex marriage ruling, however, the Loving decision was unanimous. By having all nine justices sign onto that ruling, the Warren court sent a strong signal to the nation that racially discriminatory marriage laws were intolerable under the Constitution. It would have been a strong statement from the court about the primacy of the Constitution over prejudice had the Roberts court been similarly unanimous with respect to the equal rights of gay and lesbian couples.

Even so, standing among the crowds of happy Americans celebrating the victory for marriage equality on the courthouse steps, it didn’t seem to matter. The nation was continuing along its arc of progress, and history was being made. Roberts, however, chose to make himself a footnote to that history rather than be a part of it.