New Senate gun measure unveiled, and this one's bipartisan WASHINGTON - A bipartisan group of senators unveiled a new measure Monday to combat illegal gun trafficking, a sign of momentum for one element of President Obama's initiative to reduce gun violence. The primary focus of the bill is to combat so-called straw purchasing, in which a person who is legally eligible to buy a gun does so for someone who is prohibited from purchasing or owning a firearm. The proposal would impose stiff penalties for both straw purchasers and those who sell to them. It would also explicitly define gun trafficking as a federal crime. Law enforcement officials have said the absence of such laws has hampered their ability to stop illegal firearms trafficking. Sen. Patrick J. Leahy (D-Vt.), the bill's co-sponsor and chair of the Senate Judiciary Committee, said the "common sense" proposal would address those gaps in the law. "Our bill was drafted at the request of law enforcement," Leahy said. It will provide needed tools to fight against the drug cartels and other criminals who threaten our communities. It will not undermine the 2nd Amendment rights of lawful gun owners. The bill blends two existing anti-trafficking proposals: one introduced by Leahy and Sen. Richard J. Durbin (D-Ill.), and another from Sen. Kirsten Gillibrand (D-N.Y.) and Sen. Mark Steven Kirk (R-Ill.). All four senators co-sponsor this new proposal, as well as Sen. Richard Blumenthal (D-Conn.) and Sen. Susan Collins (R-Maine). With two Republicans on board, the bill has the most bipartisan support of the major gun bills now winding through Congress. Its backers are continuing to reach out to other Republican senators, particularly Sen. Charles E. Grassley of Iowa, the top Republican on the Judiciary Committee who has an A rating from the National Rifle Assn. While groups like the NRA have ardently opposed other elements of Obama's gun control package, such as an assault weapons ban and an expansion of background checks, gun rights supporters have been relatively quiet on anti-trafficking proposals. But there have been pockets of push-back: Last week, Gun Owners of America urged members to call their senators to block the earlier version of Leahy and Durbin's bill. The group did not respond to calls for comment Monday on the new agreement. The Senate Judiciary Committee will deliberate the trafficking bill and other gun measures Thursday. A separate group of senators, led by Charles E. Schumer (D-N.Y.) and Tom Coburn (R-Okla.) have been working on a bipartisan universal background check bill, but negotiations have stalled over disagreements over record-keeping for private sales. Twitter: @melmason