The U.N.’s 193 members have until Friday to reach an agreement
to the treaty to regulate weapons exports. A first draft released Tuesday angered
advocacy groups who want the treaty’s provisions
strengthened before the treaty is finalized.

{mosads}Moran’s letter, sent to President Obama and Secretary of
State Hillary Clinton, said the draft treaty implies an expansion of federal
firearms controls that would be “unacceptable” by Second Amendment grounds.

“Today, the Senate sends a powerful message to the Obama
Administration: an Arms Trade Treaty that does not protect ownership of
civilian firearms will fail in the Senate,” Moran writes. “Our firearm freedoms
are not negotiable.”

Moran’s letter is signed by all but four Republicans, and
eight Democrats are also on board.

The Republicans not on the letter are Sens. John McCain
(Ariz.), Richard Lugar (Ind.), Scott Brown (Mass.) and Mark Kirk (Ill.).

When asked about not being on Moran’s letter, McCain, Lugar
and Brown all told The Hill they were not familiar with Moran’s letter opposing
the treaty. Kirk has been away from the Senate after suffering a stroke.

While not signing on with Moran’s letter does not mean the
senators won’t eventually oppose the treaty — as the details have not been
finalized yet — the NRA could try to make it a political problem for senators
on the fence.

The CEO of the powerful gun lobby, Wayne LaPierre, said in
his speech at the arms treaty conference that 58 senators were lined up to
oppose the treaty, based on a Senate letter from 2011.

If the 51 senators on Moran’s letter remain opposed to the
treaty’s final language, it will effectively kill any chance of ratification, which
would need a two-thirds vote.

Supporters of the treaty have argued that the Second
Amendment concerns being raised are invalid, because the Constitution would
already trump any international law.

They argue that the treaty would bring much of the world in
line with U.S. standards without affecting laws that govern domestic sales, and
that removing civilian arms from the treaty would leave it gutted.

The Bush administration was opposed to the treaty, but the
Obama administration reversed the U.S. position and signed onto the effort.