Sen. Jim DeMint (R-S.C.), the headliner for the gathering, is considered the 2012 dream candidate for some in the conservative movement, but he's ruled out a run for the White House next year, the Washington Post reported earlier this week.
King is billing Saturday's event as a "mini CPAC," a nod to the annual Conservative Political Action Conference that attracted a slew of rumored presidential contenders to Washington, D.C. last month.
"The idea is to bring the presidential candidates together under one roof, the activists under one roof, give them access to each other, exchange ideas and help shape this agenda going forward," King told The Hill earlier this month.
The gathering comes as the 2012 race received a jolt from Bachmann, who moved closer to an official run this week, and Pawlenty, who became the first top-tier contender to form an official exploratory committee.
Saturday's guest list, though, is as notable for who isn't attending as much as it is for which candidates will take the stage. A foursome of former governors who are among the most known contenders for the Republican nod in 2012: Former Arkansas Gov. Mike Huckabee, former Minnesota Gov. Tim Pawlenty, former Massachusetts Gov. Mitt Romney and former Alaska Gov. Sarah Palin.
Aside from the chance for more face time with conservative caucus-goers, the event offers rumored hopefuls an opportunity to court King, the man who could be a kingmaker in Iowa next year.
"I waited 'til the ninth of December to endorse last time," King said of the 2008 campaign in Iowa. "And that was too long, I thought."
The congressman backed former Sen. Fred Thompson (R-Tenn.) in 2008, but didn't endorse him until nearly two weeks before the Iowa caucuses. Thompson went on to finish third in Iowa behind former Arkansas Gov. Mike Huckabee and former Massachusetts Gov. Mitt Romney.
Iowa-based strategist Bob Haus, who worked for Thompson in 2008, predicted King's backing will pay enormous dividends for whichever candidate is able to earn it ahead of next year's caucuses.
"He's sort of the Good Housekeeping stamp of approval for conservatives in the state," said Haus, who noted that even though King's endorsement of Thompson in '08 came late in the game, "it was still a big boost for us."
"It's not just the endorsement," Haus said. "He'll get on the bus and go to every campaign stop with you; he'll hop on a plane and travel wherever you want. Whatever it takes."
King said he plans to make his endorsement sometime between the Ames Straw Poll in August and November of next year in the hopes that he can exert an even greater role in the caucus process with his eventual pick.
The Iowa Republican hasn't hinted that he's leaning toward anyone in the current pack of potential GOP hopefuls, but observers have already noted his close relationship with fellow congresswoman and Tea Party favorite Michele Bachmann.
-Sean J. Miller contributed to this story.