In a piece written for the Houston Chronicle, Kelly says leaders like LaPierre have abandoned their previous support for safety measures like universal background checks "in exchange for cold hard cash" from gun manufacturers.

"LaPierre and the gun manufacturers he represents exploit people's fears," Kelly writes. "In return gun manufacturers gave LaPierre and the NRA tens of millions of dollars last year alone - and he spent almost $1 million of it on his own salary."

In 1999, LaPierre testified in favor of background checks in front of a congressional panel. But following the Newtown, Conn., shootings, LaPierre has argued that President Obama's call for expanding the requirement to include gun show and internet sales would be an unconstitutional encroachment on Second Amendment rights.

"When LaPierre and his crew of highly paid Beltway insider staff reversed their earlier support of common-sense measures like expanded background checks, they sent a strong message that instead of standing with the 3 million of your members who supported background checks, they were working on behalf of the manufacturers' profit margins instead," Kelly argues.

Kelly, a gun owner, began advocating for stronger gun controls after the 2011 Tucson shooting that badly injured his wife and left six dead. He and Giffords have founded Americans for Responsible Solutions, a political action committee with the mission to counterbalance gun lobby spending in next year's election.

The NRA annual conference is expected to draw some 70,000 supporters -- top Republicans including Texas Gov. Rick Perry and Sen. Ted CruzRafael (Ted) Edward CruzThe Hill's Morning Report - Sponsored by Facebook - Trump previews SCOTUS nominee as 'totally brilliant' Cruz blocks amended resolution honoring Ginsburg over language about her dying wish Trump argues full Supreme Court needed to settle potential election disputes MORE (R-Texas) addressed the gathering on Friday.

In his remarks opening the conference Friday, LaPierre warned that the "political and media elites" were attempting to "destroy us and every ounce of our freedom."