(CNN) Donald Trump is issuing a dire warning to his supporters: You're getting ripped off.

"The system, folks, is rigged," Trump told supporters at a rally Monday night in Albany, New York. "It's a rigged, disgusting, dirty system."

Trump is coming to grips with the creeping possibility that he could narrowly lose the Republican nomination at a contested GOP convention despite landing in Cleveland with the most delegates. And his latest comments follow a series of victories by Ted Cruz's well-oiled delegate wrangling machine at state and county Republican conventions, most recently this weekend when the Texas senator swept the Colorado Republican convention -- wins that are fueling Cruz in the event neither of the two men capture the 1,237 delegates needed to avoid a brokered convention.

And with party elites continuing to rally around efforts to derail and delegitimize his candidacy, Trump is feeling the heat -- and using it to sow new outrage with his backers.

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His return fire could land with deadly impact, galvanizing his millions of supporters into an angry revolt against the Republican Party should he lose the nomination as a result of a contested convention.

"I say this to the RNC and I say it to the Republican Party. You're going to have a big problem folks because there are people that don't like what's going on," Trump said at a Rochester, New York, rally on Sunday during which he referred to the party's nominating process as "crooked" or "corrupt" seven times during his speech.

He also called attention eight times during that speech to the "millions" of votes he has pulled during the primary -- nearly 2 million more than Cruz.

RNC chairman Reince Priebus said the rules that Trump is criticizing are "nothing new."

"The rules were set last year. Nothing mysterious --nothing new. The rules have not changed. The rules are the same. Nothing different," Priebus tweeted Monday

The rules were set last year. Nothing mysterious --nothing new. The rules have not changed. The rules are the same. Nothing different. — Reince Priebus (@Reince) April 12, 2016

At a rally in San Diego, Cruz told Trump: You lost, fair and square.

"Donald, it ain't stealing when the voters vote against you. It is the voters reclaiming this country," Cruz said Monday. "65,000 people voted in the state of Colorado. They just didn't vote for you. They voted for our campaign."

But voters at Trump rallies are already sharing the front-runner's outrage.

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Julia Digioacchino said ahead of Trump's rally Monday night in Albany that she feels GOP party officials are acting "like they know better" than voters like her.

"Here is the Republican Party, instead of listening to its constituents -- to the majority of America -- who are saying this is what we want, they're not backing him up. Instead they're rallying against him, which in turn, they're rallying against us," said the 37-year-old from Saratoga, New York.

Amy Almy, a 48-year-old hairdresser who also attended Trump's rally Monday, said she now feels "naïve" for not realizing that "everything was so fixed."

Trump argues that this is about more than just him, pulling in Bernie Sanders and his fight against Hillary Clinton and the establishment for the Democratic Party nod -- into the fray. The message from Trump is that the power brokers on both sides are trying to rig the game.

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"You see what's happening to me and Bernie Sanders," Trump said Sunday in Rochester, New York. "It's a corrupt deal going on."

Six in 10 Republican voters said in a recent CNN/ORC poll that if no major candidate earns a majority of the delegates headed into the convention, those delegates should nominate the candidate who entered with the largest pool of delegates. That candidate would most almost certainly be Trump.

Trump's opponents, meanwhile, are shaking off accusations of foul play and saying Trump is failing to follow the rules.

Charlie Black, a veteran Republican strategist who is crafting a plan that would see Ohio Gov. John Kasich emerge as the nominee at a brokered convention, dismissed Trump supporters who feel they've been deceived.

"So what? So what? That's not how it works," Black said. "If he can't get a majority of the delegates, somebody else will and that's the person that won it fair and square."

"It's about the delegates, it's not about his ego," Black added of Trump, who has benefited from winner-take-all primary rules in several states to earn a larger share of delegates than he has votes.

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Colorado Sen. Cory Gardner on Monday night took to Twitter -- one of Trump's favorite stomping grounds -- to troll Trump.

"How on earth are you going to defeat ISIS if you can't figure out the @cologop convention?" Gardner tweeted, one of several in a string from his account.

How on earth are you going to defeat ISIS if you can't figure out the @cologop convention? -CG #copolitics — Cory Gardner (@CoryGardner) April 12, 2016

Cruz spokeswoman Catherine Frazier dismissed Trump's complaints as "sour grapes" and said that the Cruz campaign has simply "worked hard to build a superior organization and are working within the process and rules that have been established" after Trump's newly-minted convention manager Paul Manafort accused the Cruz campaign of "Gestapo tactics."

'Absolute destruction'

Black downplayed the potential of a fractured Republican Party should Trump fail to cinch the nomination at a brokered convention, but Trump's allies are painting a disastrous picture.

"If there are shenanigans, it's not straightforward, all of those millions of people that Donald Trump has brought into the arena are not going to stay there, and the Republicans are going to lose," former presidential contender turned Trump supporter Ben Carson said late last month on Fox News. "It's going to be absolute destruction."

Jesse Benton, the chief strategist to a pro-Trump super PAC, described an equally grim outcome.

"It would be such a suicidal move for the party to nominate anybody besides Donald Trump," Benton said. "If they decide to push millions of people out of the process, it's going to be devastating."

Manafort on board

But while Trump and his supporters are warning of an establishment effort to subvert the popular outcome, the billionaire is also beginning to look for ways to outgun his opponents within the confines of the system.

Manafort's hire as Trump's convention manager added decades of political experience and convention expertise to the campaign. Manafort is leading the campaign's efforts to clinch the 1,237 delegates needed to win the nomination and working to woo unbound delegates who could swing the needle.

His hire came after Trump only recently came to the realization that he could very well win more delegates than his opponents and yet still leave the Cleveland convention without the crown he has been seeking.

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Trump placed a call to his longtime and now informal political adviser Roger Stone on March 25 and asked if party elites could truly "screw" him out of the nomination at a brokered convention, according to a source with knowledge of the conversation.

Stone recommended Trump hire Manafort and by the end of the weekend, Manafort was on board.

"He also understands that there becomes a time when winning isn't enough , but how you win and how much you win. And he recognized this was the time," Manafort said last week on CNN, explaining Trump's decision to shift gears.

But while those gears quietly churn with his blessing, Trump's outrage is only growing louder.

"We've got a corrupt system. It's not right," Trump said on Sunday. "And we've got to do something about it."