The Republican National Committee's chairman fired back at Donald Trump late Tuesday after the billionaire White House hopeful claimed the party's process for selecting a presidential candidate was "stacked against me."
Trump has been outmaneuvered by rival Ted Cruz in a series of recent state meetings to select national convention delegates, and says the process was set up to protect party insiders and shut out insurgent candidates.
At a CNN town hall on Tuesday night, Trump launched yet another attack on the RNC.
"I know the rules very well, but I know it's stacked against me by the establishment," the GOP frontrunner said.
But RNC chairman Reince Priebus battled back against Trump's criticism.
“Nomination process known for a year + beyond. It's the responsibility of the campaigns to understand it. Complaints now? Give us all a break,” he tweeted.
Earlier, Trump alleged the GOP's selection process was "absolutely rigged ... a phony deal" after Cruz swept Colorado's 34 delegates over the weekend.
"The Republican National Committee, they should be ashamed of themselves for allowing this to kind of crap to happen. The rules are no good when they don't count your vote ... like in Colorado," he said on Tuesday at a rally in Rome, New York. "The rules are no good when you have to play dirty tricks to pick up delegates."
And on Sunday, Trump tweeted: “I win a state in votes and then get non-representative delegates because they are offered all sorts of goodies by Cruz campaign. Bad system!"
Cruz's campaign won each of Colorado's GOP delegates at its state and congressional district conventions after a similarly strong outcome in North Dakota the week prior. In states that have already held their primaries or caucuses — like Tennessee, Arizona and Iowa — the Cruz campaign has effectively positioned its own supporters as Trump delegates in preparation for a second or third ballot that would allow them to vote for Cruz.
"The party is playing dirty. We've got to show the Republican Party that you've been disenfranchised," Trump said. "You gotta show the Republican Party you can't get away with this any longer."
Trump now leads the Republican field with 756 delegates — or 45 percent of all delegates awarded to date. Yet he has won about 37 percent of all votes in the primaries, according to the NBC analysis, meaning Trump's delegate support is greater than his actual support from voters.
As Trump lashed out at fellow Republicans, his campaign was recovering from a string of missteps.
Related: Infighting, Frustration Rile Trump's Team: Sources
On Tuesday, Trump bragged it had won the support of Bob Vander Plaats, an evangelical leader and the head of The Family Leader conservative group.
The problem was, Vander Plaats is a prominent supporter of the New York real estate tycoon's main rival in the primary, Ted Cruz.
A spokeswoman for the Trump campaign later told NBC News that the candidate had in fact meant to call out another senior evangelical, Liberty University President Jerry Falwell Jr.
And on Monday, the candidate conceded that two of his children — Eric and Ivanka Trump — had failed to register as Republicans in New York in time to be eligible to vote in time for the April 19 primary.
"They were unaware of the rules and they didn't register in time," Trump said on Fox News. "So they feel very, very guilty. They feel very guilty but it's fine."
"Eric and Ivanka, I guess, won't be voting," Trump added.
