A man blows kisses to the crowd while riding in a car in the San Francisco gay pride parade, two days after the U.S. Supreme Court's landmark decision that legalized same-sex marriage throughout the country in San Francisco, California June 28, 2015. [Photo/Agencies]

The United States Supreme Court's recent ruling legitimizing same-sex marriage has sparked debates across the world. Some are calling it the most important US court verdict since the abrogation of the ban on interracial marriage in 1967, while others say the decision could upset the traditional outlook on family and compromise the basic values enshrined in the US Constitution.

A typical holder of the latter view is US Chief Justice John Roberts, who believes the ruling goes beyond the power vested in the judges, because it means only a few people (the judges) determine what American people as a whole can do. Such an argument is a kind of emotional ventilation.

The fact is that, the US Constitution endows the Supreme Court with the power of "judicial review", which means it can rule whether legislation passed by the US Congress is valid or invalid. And it is indeed empowered to make or amend laws.

In other words, the Supreme Court can scrutinize the laws passed by the Congress and the regulations and rules promulgated by states, and approve or disapprove of them. While scrutinizing legislation, the Supreme Court essentially plays the role of the Constitution's patron saint. Its power of judicial review is actually a special power of legislation. And although the Supreme Court seldom uses the judicial review power, its every verdict lays out some basic legal principles, which will play a crucial role in judicial practices.

Simply assuming that in the US, only the legislative branch has the prerogative to make laws, the executive wing only has the power to govern, and the judicial branch can only interpret and apply the laws would be a distortion of the separation of powers. The importance of the separation of powers vis-à-vis the legislature, executive and judiciary lies in the power balance. Through judicial cases, the US Supreme Court can revise laws approved by the Congress and also change decisions made by the government.

While doing all this, however, the US Supreme Court has to abide by the Constitution, as any verdict in violation of the Constitution can be overruled through other litigations. The balance among the legislature, executive and judiciary in the US is not a static but dynamic balance. Hence, Roberts' opposition to the ruling on same-sex marriage is an emotional expression - also, as required by law, he did not submit any legal evidence to justify his stance despite being the chief justice of the Supreme Court.

As American jurist and economist Richard Allen Posner has said, judges opposing legalization of same-sex marriage have failed to provide any sound evidence to support their stance. Same-sex marriage will cause damage neither to national interests nor to public interests, say, by metamorphosing established human values.

The most important aspect of the US Supreme Court's ruling on same-sex marriage is that it accords equal respect to the choice of the majority and minority. Instead of viewing marriage as an obligation, the US Supreme Court only regards it as a continuity of human civilizations and treats it from the perspective of the rights people enjoy.

In this sense, the Supreme Court chief justice made a key mistake by linking marriage to childbearing. Of all people, he should have known that in most developed countries, there is no link between marriage and childbearing. Not being married in the traditional sense has not prevented even leaders of some Western countries and their partners from having children. That's why the opposition of the US Supreme Court chief justice to the same-sex marriage ruling is more of an effort to safeguard traditional values and project himself as social conservative than an effort to protect national interests or family values.

The author is a professor of Zhongnan University of Economics and Law.