With a crowd of same-sex couples and the eight openly gay and lesbian members of the Maryland Legislature standing behind him, Maryland Gov. Martin O’Malley Thursday afternoon signed the Civil Marriage Protection Act, which calls for legalizing same-sex marriage in the state.

House of Delegates Speaker Michael Busch (D-Anne Arundel County) and Senate President Thomas V. Mike Miller (D-Prince George’s and Calvert Counties) joined O’Malley in signing the bill before a crowd of hundreds of supporters who packed the lobby of the state capital building in Annapolis.

“We are all Americans. And all of us at end of the day want the same thing for our children. We want them to live in a loving, caring, and committed home that is protected equally under the law,” O’Malley said minutes before signing the bill.

O’Malley made no mention of a voter referendum expected to be placed on the ballot in November calling for killing the bill before it becomes law. But his brief remarks at the bill signing ceremony appeared to reflect the themes that Annapolis observers expect O’Malley to use to defend the bill before voters in the fall.

“For a free and diverse people, for people of many faiths, for a people committed to the principle of religious freedom, the way forward is always found through greater respect for the equal rights of all, for the eminent dignity of all,” O’Malley said.

“Religious freedom was the very reason for our state’s founding and the heart of religious freedom is the freedom of individual conscience,” he said. “If there is a thread that unites all of our work here it is the thread of human dignity, the dignity of work, the dignity of the job, the dignity of every child’s health, the dignity of every individual.”

After signing the bill at a table placed at the foot of a curved, marble staircase where dozens of supporters stood, O’Malley handed the legislation to Busch and Miller, who placed their signature on the document.

Miller voted against the bill; Busch voted for it.

“The bill is signed,” O’Malley declared, triggering a burst of applause and cheers from the crowd.

Many of the same-sex couples in the audience held young children in their arms and embraced one another as O’Malley handed a collection of pens he used to sign the measure to well-wishers who rushed up to the governor to shake his hand.

Officials with Marylanders for Marriage Equality, the coalition of LGBT and straight allied groups that coordinated the effort to pass the bill in the legislature said that, while celebrating their legislative victory on Thursday, they were gearing up for the referendum fight.

Most agreed that O’Malley’s signature on the Civil Marriage Protection Act was the kick-off for what political observers predict will be an acrimonious referendum campaign in which opponents, as they have in other states, will warn that legalizing same-sex marriage would result in the “teaching” of homosexuality in elementary schools.

Joe Solmonese, president of the Human Rights Campaign, which initiated the Marylanders for Marriage coalition, said he was hopeful that the same-sex marriage law would survive a referendum. He pointed to public opinion polls showing Maryland voters support legalizing same-sex marriage by a slim majority over those who oppose it.

“We recognize there is a great deal of work to do between now and November and we stand ready and committed to do the work,” he said.

“The changes in the hearts and minds of people on this issue are moving so rapidly. A year now is like a decade in this fight,” he said. “So the strength of this legislative victory and this being a presidential election year and the turn out being what it will be, I’m optimistic about the prospects for winning.”

Lesbian House of Delegates member Heather Mizeur (D-Montgomery County) and her gay colleagues, Del. Peter Murphy (D-Charles County) and Del. Luke Clippinger (D-Baltimore City) agreed with Solmonese’s assessment.

The state Board of Elections on Wednesday approved the language for the referendum petition; opponents are awaiting written confirmation from the board to begin gathering signatures, according to an AP report. Petition drafts filed by opponents Del. Neil Parrott and the Maryland Marriage Alliance contain typos but are otherwise compliant, according to the AP.

Opponents were expected to gather the required number of petition signatures needed to place the referendum on the ballot for the November election.

The referendum campaign received a boost last Friday, when the Fox TV station in Baltimore, WBFF, posted a prominent link to the website gathering signatures for the referendum on its homepage.

Scott Livingston, news director at WBFF, denied any corporate involvement in promoting the referendum campaign.

“We are not endorsing any element of this debate,” Livingston told the Blade. “We see it as a political process. Our goal is letting viewers understand they have a voice in the debate.” He added that the site has now been “modified.”

The link that previously sent readers directly to the petition site now goes to a new page within the WBFF site that also includes a link to Equality Maryland’s website. The change followed what Livingston characterized as a “handful” of complaints from WBFF viewers.

The governor’s bill signing ceremony took place one week after the Maryland Senate voted 25 to 22 to approve the marriage bill. The vote came after senators supporting the bill defeated six hostile amendments introduced by opponents.

The previous week, the state’s House of Delegates passed the bill with a razor-thin two-vote margin.