Capping off a year of historic victories, the New Mexico high court handed down a unanimous ruling on Thursday granting same-sex couples the ability to wed in the state.

The 5-0 decision is written by Justice Edward Chavez, who concludes the current statutory scheme of the marriage law violates the Equal Protection Clause under Article II, Section 18, of the state constitution.

“We hold that the State of New Mexico is constitutionally required to allow same-gender couples to marry and must extend to them the rights, protections, and responsibilities that derive from civil marriage under New Mexico law,” the ruling states.

The ruling, which takes effect immediately, makes New Mexico the 17th state with marriage equality on the books. It also retroactively affirms the same-sex marriages for couples who already wed after obtaining marriage licenses from county clerks in the state.

The parties in the lawsuit, Griego v. Oliver, were six same-sex couples as well as all 33 of the state’s county clerks, who sought clarification on whether the state law enabled them to deliver marriage licenses to gay couples. Representing the same-sex couples were the American Civil Liberties Union of New Mexico, the national ACLU, the National Center for Lesbian Rights, the law firm of Sutin, Thayer & Browne APC as well as New Mexico attorneys Maureen Sanders, N. Lynn Perls and J. Kate Girard.

Laura Schauer Ives, legal director for ACLU-New Mexico, said the decision represents a “historic and joyful day for New Mexico.”

“As a state, we have always strived to treat all families with dignity and respect, and today’s decision allowing loving, committed same sex couples to marry continues that tradition,” Schauer Ives said. “The more than 1,000 same-sex couples who have already married in New Mexico can now rest certain knowing their marriages will be recognized and respected by our state.”

Camilla Taylor, National Marriage Project Director for Lambda Legal, commended her colleagues in the LGBT advocacy community for leading the way to a favorable decision on marriage equality in New Mexico.

“This beautiful unanimous decision explicitly underscores the argument we and our sister organizations have long made: denying same-sex couples the ability to marry imposes significant emotional and dignitary harm and is discrimination, pure and simple,” Taylor said.

New Mexico Gov. Suzanne Martinez, who opposes same-sex marriage but didn’t actively defend the marriage law, said in a statement she’ll abide by decision, but wish it were settled differently.

“My personal views on this issue are well-known, and I’m confident that most New Mexicans believe, like I do, that it should have been settled by a vote of the people,” Martinez said. “Instead, the Supreme Court stepped in and rendered their decision. While there will surely be intense debate about this decision moving forward, I encourage New Mexicans to continue to respect one another in their discourse, as this is an important issue for many New Mexicans on both sides.”

White House Press Secretary Jay Carney said immediate after the ruling he had no “official reaction,” but offered some thoughts.

“I would say that we welcome that ruling, and this is another example of the extraordinary progress that’s been made when it comes to equal rights for LGBT Americans in this country,” Carney said.

Justices make use of the June decision from the U.S. Supreme Court against Section 3 of the Defense of Marriage Act, noting the decision leaves marriage equality as the only option for same-sex couples to receive the federal benefits and for the state to avoid a federal challenge to its state law.

“Interpreting our statutes to authorize committed same-gender couples to enter into civil marriage will grant them the rights and privileges available to opposite-gender married couples in approximately one thousand statutes and federal regulations that refer to a person’s marital status, thereby avoiding a constitutional challenge on that basis,” the decision states.

The decision is the culmination of a drawn-out process over the course of 2013. It started in March with Santa Fe Mayor David Coss introducing a resolution, later approved the city council, saying marriage equality was already legal in New Mexico because of the gender-neutral construction of some portions of state law. That’s the conclusion Judge Alan Malott reached in a decision earlier this year extending marriage equality to Bernalillo and Santa Fe counties.

Notably, the court rejects in its decision the notion that marriage is already legal under the current state statutory scheme, observing that the legislature has passed laws, such as one changing the marriage application forms in 1961, defining marriage in opposite-sex terms.

“Thus, we conclude that a mix of gender-neutral and gender-specific terminology in the domestic relations statutes does not mean that the Legislature intended to authorize marriage between same-gender couples,” the decision states. “On the contrary, we conclude that the statutory scheme reflects a legislative intent to prohibit same-gender marriages.”

LGBT groups followed up with the Santa Fe resolution by filing a lawsuit on behalf of same-sex couples seeking to wed in New Mexico. Attorney General Gary King issued an opinion saying he wouldn’t defend the marriage law against a legal challenge in court on the basis that the law was unconstitutional.

Prior to the ruling from the New Mexico Supreme Court, a total of eight county clerks were already distributing marriage licenses to same-sex couples either through court order as a result of the litigation or on their own volition based on their interpretation of state law. An estimated 58.5 percent of New Mexico’s population had access to marriage equality prior to the Supreme Court ruling.

Attorney General King and plaintiffs in the case were pushing the idea that gays and lesbians are a suspect class and laws related to sexual orientation should be subject to heightened scrutiny — a idea with which New Mexico Supreme Court concurs because of the history of persecution faced by the LGBT community.

“Therefore, we conclude that intermediate scrutiny must be applied in this case because the LGBT community is a discrete group that has been subjected to a history of purposeful discrimination, and it has not had sufficient political strength to protect itself from such discrimination,” the ruling states.

It’s possible the opponents of the decision could place a state constitutional amendment on the ballot in 2014 that would rescind the decision, but only by legislative referral, not by initiative petition. It’s unclear at this time what the legislature will do. Democrats hold strong majorities in both chambers of the New Mexico legislature.

Brian Brown, president of the anti-gay National Organization for Marriage, promised in a statement to pursue action to protect people in New Mexico who don’t support same-sex marriage.

“Once again, activists judges have thrown out the historic legal understanding of marriage in New Mexico,” Brown said. “This is a continuation of a very dangerous rush towards silencing people of faith who simply believe marriage to be the union of one man and one woman. The National Organization for Marriage will do everything in its power to protect believers of true marriage in New Mexico and around the nation from the fallout of radical judges who deny the truth of marriage.”

Marc Solomon, national campaign director of Freedom to Marry, said his organization is prepared to fight to make sure the New Mexico decision stays in place.

“We have a campaign that we played a lead role in setting up and are on the board of, New Mexico Unites for Marriage, to protect the decision and defeat any efforts to amend the constitution,” Solomon said. “We’ve hired a campaign manager and there’s a field and media team on the ground, lobbyists, and more. It’s cochaired by former Republican Gov. Gary Johnson and Congresswoman Michelle Lujan Grisham.”