At least a dozen firearms will be raffled off at the $75-per-person event, according to promotional materials, including at least two safes filled with guns.
Grayslake resident Patt Heise said she read news reports about the event on Wednesday and was shocked it would be happening so soon after 58 people were killed in Las Vegas the largest mass shooting in modern American history.
"The fact that Lake County Republicans are auctioning off semi-automatic weapons two weeks after Las Vegas is nauseating. I don't know how else to put it," Heise said.
Heise, who belongs to a grass-roots political group called People over Party, spread the word about the plans, and in just over a day, 16 groups joined the protest.
Peaceful Communities, an all-volunteer organization that works to reduce gun violence, is going to sponsor the protest.
The members of the Lake County Republicans who organized the event could not be reached by phone or email Thursday evening for comment.
Mark Shaw, the Lake County GOP chairman, told the Chicago Tribune that a portion of the dinner proceeds would be donated to the Las Vegas Law Enforcement Assistance Fund that assists families of officers killed in the line of duty.
Lake County Board Chairman Aaron Lawlor, a Republican, said Thursday evening he would not attend, sponsor or contribute toward the 2nd Amendment Dinner.
Instead, he'll meet with members of Moms Demand Action for Gun Sense in America to speak about sensible gun law reform.
"I think that support for the Second Amendment and support for sensible gun laws are not mutually exclusive," Lawlor said.
"I think (having the dinner) two weeks after nation's largest mass shooting is in poor taste. It is a bad time to do this, especially when folks are drinking."
Moms Demand Action is a national organization formed in 2012 in response to the mass shooting at Sandy Hook Elementary School.
Moms Demand Action is also going to attend the protest along with Lake County Democrats, Illinois Council Against Handgun Violence and the Coalition for a Better IL 6th, among others.
The 2nd Amendment Dinner and Gun Raffle will be at Concorde Banquets in Kildeer at 20922 N. Rand Road.