WASHINGTON - Amid growing doubts that either Donald Trump or Ted Cruz can win enough delegates to win the GOP presidential nomination outright, party insiders say the race could be decided in state and local party meetings long before the national convention in July.

While high-stakes primaries and caucuses have already allocated more than half of the GOP delegates, in most states the voters' ballots don't decide who those delegates are. In the horse-trading of a contested convention, that could make all the difference.

In Texas, that process started in precinct gatherings after the March 1 primary. It will continue in county and district conventions this weekend, culminating in the state party convention in May.

In the wake of Tuesday's primaries in Florida and the Midwest that doubled Trump's lead over his nearest rival, Cruz strategists are watching the delegate-selection process closely and hope to use it to their advantage.

First, though, they have to stop Trump at the ballot box.

Cruz has raised the subject recently, encouraging supporters to vote not only for him, but for delegates who will support him through successive rounds of voting.

Texan's final hope

Experts agree that as Cruz's losses mount in the primary election - he won no states on Tuesday - his final hope rests with the party delegates in July.

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"The only credible path Cruz has now to the nomination is through a contested convention," said Mark Jones, a political scientist at Rice University. "Trump's only advantage at the convention is the first ballot. Once you move away from the first ballot, many of the Trump delegates will want to back Cruz."

Even with Trump's lead of at least 673 delegates, he would need to win more than 60 percent of the remaining delegates to clinch the nomination. Cruz, with 411 delegates, would have to win about 80 percent - mathematically attainable, but virtually impossible.

Those numbers suggest that Cruz's path to the nomination lies in blocking Trump from getting the requisite number of delegates and thus throwing the convention into multiple rounds of voting that would continue, under current rules, until a candidate gets a majority.

Delegates from most states become free agents after the first round, but rules among states vary. The Texas Republican Party binds its 155 delegates until the third round, limiting their leverage somewhat.

For now, 104 of the state's GOP delegates will be bound to Cruz; 48 will be assigned to Trump; and three are committed to U.S. Sen. Marco Rubio, who dropped out Tuesday after losing his home state of Florida. (Under state party rules, Rubio's delegates will likely be free agents in the second round of balloting, assuming he doesn't hit 20 percent in the first round.)

The personal styles of the individual delegates could come into play to an even greater extent if the convention deadlocks on the first round. Given the organizational strength behind Cruz's grass-roots support in Texas and elsewhere - plus the penchant of longtime party activists to get involved in the process - many analysts give the advantage to Cruz in a full-on floor fight.

"A lot of the Trump delegates are going to be Cruz supporters," said Rick Shaftan, a GOP operative who runs a pro-Cruz Super PAC called Courageous Conservatives.

Current rules of the GOP convention require a series of re-votes if no candidate wins more than 50 percent of delegates in the initial balloting. A spokesperson for the 2016 convention said the details of that process will be spelled out when the GOP Rules Committee meets the week before the convention. But adding to the uncertainty, those rules are still subject to negotiation among delegates representing the campaigns.

"With so many states, just think how complicated the rules can make this stuff," said Aaron Crawford, a scholar at Southern Methodist University's Center for Presidential History.

Former Texas Republican Party Chair Steve Munisteri, who attended the last contested GOP convention in 1976, said the campaigns are well advised to strategize in every step of the process, from precinct meetings to state and national conventions.

"Delegates did switch from candidates they were pledged for to other candidates, and they changed some of the rules while they were there," he said. "In a contested convention, every delegate will be talked to."

'Laborious process'

The Cruz campaign is preparing for that likelihood. As Cruz took a pummeling in a round of primary votes Tuesday night, his chief strategist, Jason Johnson, told reporters that aides were hosting meetings across the country in support of delegates who would favor Cruz, even if they were obligated to back his rival in an initial vote.

"That's a county-by-county, district-by-district, state-by-state process," Johnson said. "It's very laborious."

It may well be worth the effort. Speaking Wednesday on CNBC, GOP Rules Committee member Curly Haugland said "it appears we're headed" to a contested convention. And the deciding factor, he suggested, will be the makeup of the delegate pool.

"The media has created the perception that the voters will decide the nomination," he said. "Political parties choose their nominee, not the general public."

While a contested convention would benefit Cruz, it could spell trouble for Trump. Speaking to CNN on Wednesday, Trump said he anticipated "riots" if he entered the convention with the most pledged delegates and left without the nomination.

But in recent weeks, growing chatter in Republican circles has suggested that establishment forces, anxious to avoid handing their party flag to Trump in July, believe a contested convention could be the best option.

"Imagine how ugly this could get," Crawford said. "It could turn very ugly."