Maryland Gov. Martin O'Malley at a gun-control rally in March. (Photo by Patrick Smith/Getty Images)

Maryland Gov. Martin O’Malley touted a list of his achievements, including the legalization of same-sex marriage and the repeal of the death penalty, during an address Saturday to a national gathering of an influential liberal legal organization.

Speaking to the American Constitution Society’s convention in the District, O’Malley (D) also touched on his efforts to extend in-state college tuition rates to undocumented immigrants, pass “nation-leading” gun-control laws and spend more on an array of priorities, including education and substance-abuse treatment.

Such policies reflect a respect for “equal rights and inclusion” and “the dignity of every individual” and have strengthened his state, the governor said.

“These things make our state more innovative as well as more just, more creative as well as more open, a better place for business, a better place for job creation,” O’Malley told a crowd of several hundred in a hotel ballroom at the Capital Hilton.

He was billed as a featured speaker at the gathering of a group founded more than a decade ago as a counterweight to the Federalist Society, a conservative network that has sought to reform the U.S. legal system.

The clout of the American Constitution Society grew considerably with the election of President Obama, who has tapped its members, including Attorney General Eric H. Holder Jr., for legal appointments and advice.

In his remarks, O’Malley, who is weighing a 2016 presidential bid, said the Federalist Society and the tea party movement had worked to “constrict opportunity” for many upwardly mobile Americans, instead seeking to advance the interests of the wealthy.

“They’ve managed to halt middle-class progress for the first time in American history,” said O’Malley, who urged the audience to continue advocating for more progressive policies.

O’Malley relayed that Maryland voters ratified the state’s new laws on same-sex marriage and immigrant tuition last year after opponents petitioned them to the ballot.

He attributed the passage of the legalization of gay nuptials to “a message that focused on human dignity, the idea that we all want the same things for our kids. We want them to be able to live in a loving, committed, stable home, protected equally under the law.”

O’Malley also acknowledged that it was not initially clear that the so-called Dream Act would win voter approval when it was the subject of a petition drive.

“At the time, the reactionary voices shouted and clamored that it was free tuition for illegal immigrants, which is was not,” O’Malley said.

The law limits in-state tuition rates to those who graduate from Maryland high schools and whose families file tax returns.

O’Malley also relayed some personal stories to the group Saturday, including that his late father inspired him and several of his siblings to become lawyers.

“Like him, we wanted to be able to stand up for people who often had no voice, whose last hope was the integrity and commitment of their attorney,” O’Malley said.

Other featured speakers at the convention included retired U.S. Supreme Court justice John Paul Stevens, Sen. Elizabeth Warren (D-Mass.) and Rep. John Lewis (D-Ga.).

O’Malley was introduced by Paul M. Smith, a member of the group’s board of directors and a lawyer who has argued numerous cases in front of the Supreme Court.

He called O’Malley “a man I suspect we’ll be seeing a lot more of in the coming months and years.”