Wisconsin Gov. Scott Walker, shown here this month in West Des Moines, Iowa, has not said whether he will participate in the Iowa straw poll if he becomes a presidential candidate. (Daniel Acker/Bloomberg)

When Republican officials in Iowa convened a planning session Thursday for their quadrennial presidential straw poll, only a handful of advisers to GOP contenders bothered to show up.

The sparse attendance and lack of enthusiasm, even from those who came, was worrying to state party brass: The straw poll — a carnival-like organizing ritual that has in past years winnowed the candidate field and marked the start of caucus season — has faded into irrelevance.

This August’s straw poll in Boone, in fact, may be the least consequential in decades. Some Republican hopefuls expect to participate only halfheartedly, while others — including former governors Jeb Bush (Fla.) and Mike Huckabee (Ark.) — are opting out altogether. And almost no one outside the fringes of the race believes a summertime victory would provide a meaningful jolt.

Thursday’s information-only meeting in Des Moines at state GOP headquarters illustrated the event’s descent. Representatives from seven official or soon-to-be-declared candidates dropped by, but none from the top tier.

Most telling was the absence of Wisconsin Gov. Scott Walker’s operation. Walker, who spent part of his childhood in Iowa and has built a fervent following of Christian activists and tea party conservatives, seems poised to bypass the straw poll and focus on next year’s caucuses.

Former Arkansas governor Mike Huckabee, who won the Iowa caucus in 2008, plans to skip the Iowa straw poll this time around. (Ross D. Franklin/AP)

The lack of interest from Huckabee and former Pennsylvania senator Rick Santorum — the winners of Iowa’s past two Republican caucuses — has a similar debilitating effect.

Walker’s aversion is notable because his candidacy is one that could reap benefits from straw-poll success, elevating him as a donor-class darling who is also a favorite of the grass roots and sucking up the political oxygen from his underfunded rivals on the right.

But the risks for Walker and the rest are evident: Win, and you gain little other than momentum; underperform, and your campaign could be tagged as flat and inspiring. When former Minnesota governor Tim Pawlenty competed hard in the 2011 straw poll only to lose, he ended his campaign the next day.

“We haven’t made any commitments for anything that requires a candidate to officially declare,” Walker said this week on Laura Ingraham’s radio program, reflecting his wariness of angering Iowans but reluctance to bring a volunteer army to the Central Iowa Expo on Aug. 8 that would surely raise expectations.

Strategists for Sen. Marco Rubio (Fla.), who has surged to the fore of the 2016 pack, also did not appear Thursday. “We’re running a lean operation, so we’re only spending money to compete in contests where delegates are at stake,” said Alex Conant, Rubio’s spokesman.

Those who attended Thursday’s meeting were allies of Sen. Ted Cruz (Tex.), businessman Donald Trump, former surgeon Ben Carson, former Texas governor Rick Perry, Sen. Lindsey O. Graham (S.C.), former Silicon Valley executive Carly Fiorina and Gov. Chris Christie (N.J.). All have blocs of support but sit near the middle or bottom of national polls.

Republicans prepare to cast their vote in the 2011 Iowa straw poll in Ames, Iowa. (Charlie Neibergall/AP)

Intriguing was the presence of Christie’s adviser, Phil Valenziano. Hobbled by aides’ involvement in a bridge-closing scandal, Christie has been lagging behind for months and eyeing New Hampshire as the setting for a possible comeback. But if other center-right Republicans neglect the straw poll, his friends say, Christie could try to impress there and earn a boost.

At a book signing in Davenport, Iowa, on Thursday afternoon, Sen. Rand Paul (Ky.) said that “we ­haven’t decided” on whether to participate.

The straw poll’s unraveling can be traced to those late summer days of 2011. After tea party star Michele Bachmann, then a Republican congresswoman, topped Pawlenty and a parade of others, her campaign crashed. GOP leaders in Washington and some powerful Iowa Republicans, fed up with the spectacle and the way the event has damaged the state’s influence on presidential races, have worked to cripple it or at least tone it down.

The straw poll, with its new home in the town of Boone, will be more controlled and low key. In its previous location at Iowa State University in Ames, it had the feeling of a tailgate party, with lines of cars and tents where tickets were handed out and paper plates were piled with barbecue pork.

Worried that the state’s caucuses will be diminished if the straw poll becomes overly associated with Iowa’s role in presidential politics, Gov. Terry Branstad (R) has been at the center of the effort to lessen the straw poll’s significance.

Bush, speaking earlier this month in Iowa City, agreed. “All of the resources ought to go to the thing that matters, which is the Iowa caucuses on February 1,” he said.

For now, organizers of the straw poll remain confident that it will go on. “We never expected 100 percent participation,” Iowa GOP adviser Charlie Szold said Thursday. “In a field this large, we understand how it’s not strategic for everyone to do it. We still expect ten to twenty thousand Iowans to be part of a beloved tradition.”