I enjoyed reading US Bureau Chief Jeremy Au Yong's commentary last Thursday ("'Activist' US Supreme Court a key issue in 2016 polls").

Many conservative politicians are concerned that the Supreme Court is playing an "activist role" by ruling on important issues like marriage equality.

I disagree: A key role of the Supreme Court is to protect the constitutional rights of citizens.

By ruling in favour of marriage equality, the Supreme Court did not change the definition of marriage. Rather, as the arbiter of the Constitution, the court upheld a fundamental right that is already found in the Constitution.

In the opinion of the court, Justice Anthony Kennedy writes: "The issue before the court here is the legal question whether the Constitution protects the right of same-sex couples to marry."

By ruling in favour of marriage equality, the Supreme Court did not change the definition of marriage. Rather, as the arbiter of the Constitution, the court upheld a fundamental right that is already found in the Constitution.

The judge concluded that the due process and equal protection clauses of the Fourteenth Amendment both safeguard this fundamental right.

Robbie Straughan