But the most prominent gun-control organization, the Brady Campaign to Prevent Gun Violence, ultimately supported the bill.
A prominent gun blogger and lifelong N.R.A. member explains how the organization uses fear to get its way.
Prominent gun organizations applauded the limited American participation, and suggested that the United Nations effort was too broad.
Two weeks ago, Mr. Schumer, a prominent gun control advocate, invited Ms. Gillibrand to a news conference in Manhattan to unveil a gun control plan.
Many prominent gun control groups have since moved away from an assault ban – "through hard, bitter experience", said Matt Bennett, a gun policy expert who advised Sandy Hook Promise.
"The Connecticut state judge is obviously gaming the system for the benefit of plaintiffs," David Kopel, an attorney and prominent gun rights advocate, wrote in an email.
Shortly after the announcement, which was streamed live on Facebook, David Hogg, a senior at Marjory Stoneman Douglas High School and a newly prominent gun-control advocate, took to Twitter.
A new analysis of Romney's gun control record by prominent gun owner's rights activist Dave Kopel found that Romney "has a thin record to back up his claims of support for the Second Amendment".
The Brady Center to Prevent Gun Violence, a prominent gun reform group, has identified 52 bills it considers a priority for passage in 22 states, compared with 30 such bills two years ago.
Mr. Spitzer was the first to take the lead last July, holding closed-door meetings with prominent gun makers like Colt's Manufacturing of Hartford and Smith & Wesson of Springfield, Mass.
