ALBANY — Thousands of gun rights advocates swarmed the Capitol on Thursday, cheering as a parade of lawmakers who oppose New York's new gun control law lauded the Second Amendment and blasted the new measure's backers.

"This is probably one of the most egregious acts by government I've seen defying our nation's history," said Assembly Minority Leader Brian Kolb, R-Canandaigua. "It's time to repeal this law."

"I have never seen a crowd this big," said Sen. John Bonacic, a Republican from the Hudson Valley. "You inspire me to fight on."

Called the NY SAFE Act by Gov. Andrew Cuomo, its principal supporter, the gun control measure broadened the definition of banned assault weapons and made magazines containing more than seven bullets unlawful. It also increased penalties for illegal gun possession, reduced public access to gun permit information and allowed mental health professionals to report concerns about a gun-owning patient who might be at risk of harming himself or others.

The bill passed quickly last month through a "message of necessity" that waived the legally required three-day waiting period. The Senate, led by a Republican-dominated coalition, passed the measure by a 43-18 vote less than two hours after the bill's text became public. The Democrat-dominated Assembly passed the bill the next day, and Cuomo signed it.

Although Senate Republican Leader Dean Skelos voted for the bill and allowed it to go to the floor — a key action that let it become law — rally organizers directed their enmity at Cuomo.

Several members of the Republican conference spoke at the rally to denounce the law. They said they are upset by the process under which it was considered, and the effect it has on law-abiding citizens who own now-banned rifles and will have to register their firearms or face prosecution.

There doesn't appear to be enough legislative support to significantly amend the law, though Sen. Kathy Marchione, R-Halfmoon, on Thursday introduced a bill to repeal much of it. The state's top lawmakers have said they are considering some corrections to the bill, including an exemption for film and television producers that use fake guns. The New York State Rifle and Pistol Association is working on a legal challenge to the law that the group hopes to file next week.

The group's president, Tom King, had said 10,000 people would come to the rally. A dense crowd filled West Capitol Park as well as sidewalks along Swan Street, State Street and Washington Avenue; King said 118 buses and 25 vans brought in participants from around the state. State Police Lt. Robert Poisson said the crowd was "over 5,000." He said there were no law enforcement issues, and that from a police perspective the rally was "quite uneventful."

Said King: "If there weren't 10,000 people there, I'll eat 'em."

National Rifle Association President David Keene traveled to town for the rally, and told the crowd that Cuomo pushed the bill to boost his own future aspirations.

"Your governor is willing to sacrifice the Constitution, your rights as citizens and the prerogatives of his Legislature on the altar of his own ambition and the ego of Michael Bloomberg of New York City," said Keene, referring to the Big Apple's billionaire mayor, a staunch gun control advocate.

Some who took part held signs calling for Cuomo's impeachment, and others brandished doctored images of the governor with a Hitleresque mustache. None of the speakers, however, suggested either idea, though one Republican assemblyman said the governor had been "tyrannical."

Cuomo has defended the gun law, often noting that public opinion polls have found at least two-thirds of voters surveyed support it. He has characterized the dissent — including resolutions passed by half the state's counties — as the actions of a "vocal minority." A Siena Research Institute survey released earlier this month found that 50 percent of upstate voters support the measure, compared to 46 percent who were opposed.

SEIU 1199, the health care worker's union, has formed a coalition to argue and demonstrate in favor of the SAFE Act, which it says will save lives and reduce gun crime. The union had planned to bus members to the Capitol for a counter-demonstration on Thursday, but were discouraged by State Police, a union spokesman said.

Instead, SEIU is working to build a coalition of gun violence victims and plans a demonstration in New York City in favor of the law later in March.

Cuomo, appearing at an event in Brooklyn, stood by the SAFE Act.

"I'm very proud that the state finally made progress with a comprehensive bill, but an intelligent bill," Cuomo said. "I am a gun owner. This is not about taking anyone's gun. This is not about saying, 'There's no such thing as the Second Amendment.' And I think that's the fear. People think that government is going to come and literally take their guns away. That's not what it's about."

jvielkind@timesunion.com • 518-454-5081 • @JimmyVielkind