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New York City Mayor Michael Bloomberg hoped to rally support in Congress on Tuesday for stopping the flow of illegal guns but found it tough to round up a posse of like-minded lawmakers.

"If Congress is going to coddle criminals, we are going to shout it from the rooftops," said Bloomberg.

A day earlier the mayor announced the city was suing 15 out-of-state gun dealers for what he said are violations of gun purchase laws caught on undercover videotape. In the sting operation, a person would complete paperwork and a background check while purchasing a gun only to give the firearm to someone else, commonly called a "straw purchase."

The Republican mayor has made cracking down on the flow of such guns into New York a principle goal of his second term in office. He appeared Tuesday promoting legislation by Sen. Charles Schumer, D-N.Y., that would allow cities to use gun trace data to go after dealers who sell weapons to criminals.

Bloomberg also accused the National Rifle Association of blocking his efforts, charging that the organization is not protecting the Second Amendment right to bear arms but endangering the lives of civilians and police officers.

"The sad fact is that one lobbying group has rolled an enormous percentage of both houses of Congress," he said.

By trying to bar such data from public view, Bloomberg said, lawmakers are "being soft on crime."

Wayne LaPierre, the CEO of the NRA, said of Bloomberg: "I cannot figure out where he's coming from."

The gun trace data, LaPierre argued, "was being misused by trial lawyers and by antigun groups and compromising criminal investigations."

LaPierre said he didn't know all the details of Bloomberg's new lawsuit against specific dealers, but he said that the NRA essentially agrees that any dealer engaged in illegal straw purchases should be punished. "They're against the law and we have always been opposed to any type of straw-man sale," he said.

The mayor is especially irate over a bill offered by Rep. Lamar Smith, R-Texas, that would make permanent a ban on federal authorities' sharing gun trace data with local governments. Cities including New York have used such data to launch lawsuits against the gun industry.

To counter the Smith bill, Sens. Robert Menendez, D-N.J., and Hillary Rodham Clinton, D-N.Y., have offered a measure designed to make gun trace data available. It does not include all the tough antigun trafficking measures proposed in Schumer's bill.

Even with a bully pulpit and deep pockets, the billionaire mayor could not name a single lawmaker whom he had persuaded to change his or her mind on the issue of gun traces, though he said he thought a recorded vote would bring many around to his side.

Schumer said he hoped to use his legislation, which would go beyond Menendez' bill to toughen prison terms for gun traffickers and allow federal agents to more closely inspect gun dealers' inventories, as an amendment on the Senate floor to force a vote on the issue.

"I think you're going to find some surprising votes," Schumer said.