WASHINGTON » Republican leaders, searching for a fair-minded but strategically wise way to conduct the presidential primary debates, are grappling with how to manage White House contenders in a sprawling field that mixes proven politicians with provocateurs and reflects an increasingly fractious party.

The Republican National Committee’s decision last year to claim control of the 2016 debate process was welcomed by many in the party who believe Mitt Romney, the 2012 nominee, was hurt by both the pummeling and the positions he took during the 20 debates in that primary contest.

But by trying to impose order through party-sanctioned debates and limiting the number of forums, the party may have begotten an equally messy problem: who to include on stage for a 90-minute debate from a field of nearly 20 potential candidates.

As the national committee gathers in Arizona this week for its spring meeting, it will discuss how to determine the candidates who will make the cut for the first sanctioned debate, which is set for Aug. 6 in Cleveland and will air on Fox News. But there is already a robust discussion behind the scenes, with candidates who are lagging in early polls nudging the party to take an inclusive approach in the initial forums.

It is not entirely clear who will be in charge of devising or enforcing the debate criteria — that is, if there are criteria. One member of the national committee panel charged with overseeing the debates said its members had discussed ceding the decision entirely to Fox News.

At issue is how to stage a substantive discussion that is fair to viewers and the campaigns. The party has little appetite for a forum so thick with candidates that it allows for not much more than an extended "lightning round" of questions. One Republican involved in the process said a 90-minute forum with 10 candidates would offer each candidate only four to five minutes, after subtracting commercials and moderator time.

But as the 2012 primary demonstrated, televised debates can instantaneously reshape presidential races, and candidates who could face the possibility of being excluded argue any attempt to winnow the participants so early in such a fluid primary contest would be wrongheaded.

"You really shouldn’t limit participation before the Iowa caucuses," said John Brabender, former Sen. Rick Santorum’s strategist.

To Santorum’s peers in the single digits in primary polls, the Noah’s Ark-size field is an asset to be spotlighted, not a problem to be managed.

Brad Todd, a strategist supporting Gov. Bobby Jindal of Louisiana, said the party risked refighting the last political war.

"Much of the planning for these debates was done in view of 2012 and the 2012 debates, which many saw as road bumps on the way to Mitt Romney’s coronation," he said. "But that’s not the challenge we have this time. The challenge is how we get exposure to good candidates."

Allies of Jindal have been especially forceful in pressing the committee to be flexible about whom to include in the first face-offs. One idea they have floated: back-to-back debates, with seven or eight candidates, chosen at random, in each.

Of course, it is not yet clear who will still be a candidate in August, another indication of the magnitude of the party’s challenge as it takes up the subject.

It is a delicate matter: To rely on polling alone could mean barring current and former senators and governors from participating in debates that would offer them desperately needed political oxygen. And should excluded candidates try to attract attention by holding their own unsanctioned debates, they would be precluded from participating in future sanctioned debates, according to the rules adopted last year by the national committee.

Even thornier for the party is what to do about two high-profile contenders who have not previously been elected to office.

Many Republicans laboring to improve the party’s image recoil from the prospect that whatever debate-eligibility criteria are adopted could result in the barring of the only woman, Carly Fiorina, the former Hewlett-Packard chief executive, or Ben Carson, a retired neurosurgeon who is the only African-American candidate.

But could Republicans include Fiorina and Carson while keeping out such low-polling candidates as Gov. John R. Kasich of Ohio, Sen. Lindsey Graham of South Carolina, former Gov. Rick Perry of Texas or even Donald Trump?

It is possible that the party could ultimately devise some threshold involving polling, small-dollar fundraising, the size of a campaign’s staff or the number of events held by a candidate, potential measurements that are all being discussed.

But even the most equitable standards could mean barring statewide elected officials from competition, and party leaders are uneasy about setting off a backlash.

The fear, according to one party official, is that the excluded candidates could collectively use conservative websites and talk radio to foment anger at the so-called Republican establishment — an assault that could undermine the national committee’s hold on the debate process.

"There would be so much outrage if they didn’t start inclusively," Brabender said. "It would look like the party was once again playing arbiter of who they want to be nominee."

Even if the party does come up with its own standards for participation, it is evident Republican officials want to do so in concert with Fox News — a move that could help deflect the anger of candidates who are excluded.

"It’s going to be a group effort," said Reince Priebus, chairman of the Republican National Committee. "Obviously our media partners are going to have a big say in the process, as well as our party."

Michael Clemente, a Fox News executive who has been involved in some of the discussions, did not respond to an email regarding the first debate.

Steve Duprey, a national committeeman from New Hampshire who is the head of the party’s debate panel, acknowledged having many more than nine candidates onstage, the most that appeared in the 2012 debates, would be "unwieldy."

But he said his overarching goal was to pare the number of debates, spread them out fairly to the states and build a sensible schedule — so a debate on Sunday morning would not follow one on Saturday night, as happened in 2012.

"If we do nothing more than achieve those three goals," Duprey said, "regardless of how our media partners declare how many candidates get in, I’m declaring victory."

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