Northeastern University School of Law alumna Mary Bonauto, L’87, a champion for gay rights, will argue for overturning same-sex marriage bans before the U.S. Supreme Court later this month.

Bonauto was selected by the attorneys for gay and lesbian plaintiffs to present their main argument on April 28, that “equal protections” and “due process” afforded under the 14th amendment require states to issue marriage licenses to same-sex couples.

“The road that we’ve all traveled to get here has been built by so many people who believe that marriage is a fundamental right,” Bonauto said in a statement. “Same-sex couples should not be excluded from the joy, the security and the full citizenship signified by that institution.”

The Supreme Court announced in January it would hear arguments from same-sex marriage cases in Michigan, Tennessee, Ohio, and Kentucky, but that the cases would be combined into one hearing. The court said it will rule on states’ power to ban same-sex marriage and refusal to recognize out-of-state same-sex marriages.

Bonauto’s argument is based on the cases from Michigan and Kentucky, which raise the question of same-sex marriage, which is legal in 36 states.

For most of her legal career, Bonauto has worked tirelessly for equal rights for all people, specifically the right to marry for same-sex couples and the legal protections that marriage affords. Last year she became the law school’s second graduate to receive a MacArthur Fellowship.

“It is fitting indeed that this brilliant and courageous lawyer, long a pioneer on behalf of each person’s right to marry, should be selected to champion the cause at our nation’s highest court,” said School of Law Dean Jeremy Paul. “The affected individuals will be well served and the fate of all those seeking the basic right long afforded to heterosexual couples could not be in better hands. Northeastern is proud to have launched the career of this bold advocate for justice.”

Bonauto has argued and won landmark same-sex marriage cases during her time as the civil rights project director at Gay and Lesbian Advocates and Defenders. In 1999 she secured the nation’s first civil union law in Vermont, and in 2003 she successfully argued the Supreme Court case legalizing same-sex marriage in Massachusetts.

Eight years after same-​​sex couples began marrying in Massachusetts, Bonauto led GLAD’s challenges to the constitutionality of Section 3 of the Defense of Marriage Act, which defined marriage as a legal union between one man and one woman. Her work served as the model for United States v. Windsor, the case that led the U.S. Supreme Court to strike down DOMA in 2013.

In a news@Northeastern story last fall about her MacArthur Fellowship, Bonauto said each of her experiential learning opportunities at Northeastern enabled her to examine the legal system from a different vantage point, giving her a rare perspective on the many ways in which the law can be used for good. “My co-​​op experiences have been invaluable to the work I’ve done at GLAD,” Bonauto said. “We’ve been very eager to collaborate with non­profits, advocacy groups, and legal services organizations to help us move our initiatives forward.”

Bonauto’s long-​​term goals include eradicating HIV and ending LGBT discrimination in both the workplace and the classroom. “Achieving marriage equality does not mean our work is done,” she said. “Marriage equality will resolve the issue of gay marriage, but it will not ensure that LGBT students are safe in schools or LGBT employees are not discriminated on the job.”