Friday’s U.S. Supreme Court decision, which declares that same-sex couples have a constitutional right to obtain marriage licenses and partake of all the privileges and responsibilities that result, culminates what is arguably the quickest and most dramatic social and legal shift in the nation’s history.

Connecticut stands proud as a leader in this remarkable civil rights achievement.

When, in 2004, Massachusetts became the first state to begin issuing marriage licenses to homosexual couples — the result of a state Supreme Court decision that found the prohibition against such marriages a violation of the constitutional guarantee of equal treatment — many saw the concept as radical. A national backlash resulted.

By 2008, the campaign against gay marriage peaked, with 30 states banning such marriages in their constitutions, another 13 by way of statute. Connecticut took a different path, that year joining Massachusetts as the only other state at the time to find such unions constitutionally protected.

Then, something remarkable happened; public opinion began to shift. Americans increasingly questioned why their fellow citizens, who happened to be physically and emotionally attracted to persons of the same gender, should not have the same marital options as heterosexual couples. Polls now show most Americans approve of the legalization of same-sex marriages.

In parallel, the constitutional arguments for equal treatment presented by the decisions in Massachusetts, Connecticut and elsewhere began to percolate into the federal courts. Two years ago this month, with the same 5-4 split seen in Friday’s ruling, the Supreme Court constructed its foundation for the constitutional protection of same-sex marriages. It gutted the federal Defense of Marriage Act (DOMA), which had defined marriage as between a man and woman when it came to federal policies such as tax law and military benefits. This prejudicial law violated the 14th Amendment’s guarantee of “equal protection of the laws” ruled the court’s majority.

So persuasive did other federal appellate courts find the reasoning in the DOMA ruling that they began to use it to strike down as unconstitutional state prohibitions of same-sex marriage. When those appeals reached the Supreme Court, the majority completed its constitutional framework atop the DOMA-case foundation.

In writing the majority opinion, Associate Justice Anthony Kennedy, the swing vote in upholding the rights of same-sex couples, is perhaps most eloquent in making the case that the Constitution is not a stagnant document, but one that reveals itself through the illumination of time and changing attitudes.

“The generations that wrote and ratified the Bill of Rights and the Fourteenth Amendment did not presume to know the extent of freedom in all of its dimensions, and so they entrusted to future generations a charter protecting the right of all persons to enjoy liberty as we learn its meaning,” writes Justice Kennedy.

Once it was considered constitutionally permissible to permit segregation and separate treatment of a racial group, or allow the government to interfere in the medical choices between a woman and her doctor, or, most applicable to this case, ban marriages between citizens of different races. This is the case no longer. Same-sex couples will now benefit from the same constitutional enlightenment.

Dissenting justices say the court should not intervene and must leave the definition of marriage to state legislatures. Justice Kennedy forcefully responds. “Individuals need not await legislative action before asserting a fundamental right” and seeking “constitutional protection when he or she is harmed, even if the broader public disagrees and even if the legislature refuses to act.”

Supporters of this ruling should respond with magnanimity and humility, opponents with appreciation for the rule of law. In segments of this nation, the ruling is difficult to accept, but there can be no standing in City Hall doors to block access to marriage licenses.

Respecting differences of opinion will help mend divisions. Militancy will widen them.

Justice Kennedy emphasizes that the guarantee of religious freedom gives religious groups the right to define marriage as they see fit.

“The First Amendment ensures that religious organizations and persons are given proper protection as they seek to teach the principles that are … central to their lives and faiths, and to their own deep aspirations to continue the family structure they have long revered,” he writes.

Same-sex marriages will not destroy traditional marriage or families, as some warn; they will build upon the model, which could use some sprucing up.

In his conclusion, Justice Kennedy says it well.

“It would misunderstand these men and women to say they disrespect the idea of marriage. Their plea is that they do respect it, respect it so deeply that they seek to find its fulfillment for themselves.”