(CN) - New Mexico "is constitutionally required to allow same-gender couples to marry," the state Supreme Court ruled Thursday.
Writing for unanimous court, Justice Edward Chavez ruled that "barring individuals from marrying and depriving them of the rights, protections, and responsibilities of civil marriage solely because of their sexual orientation violates the Equal Protection Clause under Article II, Section 18 of the New Mexico 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."
Though the court acknowledged that "none of New Mexico's marriage statutes specifically prohibit same-gender marriages," it said the laws, "when read as a whole ... have the effect of precluding same-gender couples from marrying and benefiting from the rights, protections, and responsibilities that flow from a civil marriage."
The state's basic marriage provisions are gender-neutral, Chavez noted, but some legal forms still require a "male applicant" and a "female applicant," or signatures from a "bride" and a "groom."
Chavez also pointed out that the phrasing of many state laws limits marriage benefits to heterosexual couples.
The laws were challenged in March by six gay and lesbian couples, many of whom have been together for years and raised children together. In late August, a state judge ordered the clerks of Bernalillo and Santa Fe counties to begin issuing marriage licenses to same-sex couples. All 33 clerks in New Mexico County later intervened and asked the high court to issue a statewide ruling on whether gay and lesbian couples can marry.
Before the ruling, clerks in at least eight counties began issuing marriage licenses to gay and lesbian couples.
On Thursday, the justices ruled unanimously for the plaintiffs.
"Excluding same-gender couples from civil marriage prevents children of same-gender couples from enjoying the security that flows from the rights, protections, and responsibilities that accompany civil marriage," Chavez concluded in the 31-page ruling.
"There is no substantial relationship between New Mexico's marriage laws and the purported governmental interest of responsible childrearing," he added. "There is nothing rational about a law that penalizes children by depriving them of state and federal benefits because the government disapproves of their parents' sexual orientation."
Shannon Minter, legal director for the National Center for Lesbian Rights, called the ruling "a powerful affirmation that same-sex couples are equal members of New Mexico's diverse culture and must be given the same legal protections and respect as other families."
New Mexico joins 15 other states and the District of Columbia in legalizing gay marriage.
Read the Top 8
Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.