For the second time in three terms, the Supreme Court has agreed to consider the constitutionality of same-sex marriage. The last time around, the justices declined to take up the broad question. This time, there is every reason for them to follow the logic of their own rulings over the past 12 years and end the debate once and for all…

The 12 years since 2003 have seen enormous social change on this issue. Before the Massachusetts Supreme Judicial Court legalized same-sex marriage in November 2003, no state permitted such marriages. Today, 36 states do, along with the District of Columbia — representing more than 70 percent of all Americans. A solid and growing majority now believes in marriage equality; among those 18 to 29, support is at nearly 80 percent.

For same-sex couples and their families, friends and communities, this moment has been a long time coming. The justices have the power and the responsibility to give meaning to the promises embedded in the Constitution, and end the exclusion and inequality of gays and lesbians in America.