Republican presidential front-runner Donald TrumpDonald John TrumpGOP congressman slams Trump over report that U.S. bombed former anti-ISIS coalition headquarters US to restore 'targeted assistance' to Central American countries after migration deal Trump says lawmakers should censure Schiff MORE's campaign says Ted CruzRafael (Ted) Edward CruzThe Hill's Morning Report - Dem debate contenders take aim at Warren The Hill's Morning Report - Trump grapples with Turkey controversy This week: Congress returns to chaotic Washington MORE's campaign is now being run by the GOP establishment and "Bush people."

“The Bush people are now running Sen. Cruz’s campaign — Neil Bush, who’s spent millions of dollars invested with Common Core, and all of these other special interest groups like Goldman Sachs, like hedge fund managers,” Trump spokeswoman Katrina Pierson told Fox News on Wednesday.

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“This is going to be a very serious problem if Sen. Cruz continues to go down this path and then neither Trump or Cruz becomes the nominee.”

Trump's campaign accused Cruz, his chief rival for the nomination, of being "worse than a puppet" in a statement released after Trump's loss in the Wisconsin primary Tuesday night.

"He is a Trojan horse, being used by the party bosses attempting to steal the nomination from Mr. Trump,” the Trump campaign said.

Pierson said Wednesday it's clear that many people in the GOP establishment don't plan to support Cruz during the convention process.

Cruz can't win "on his own merits," she said.

“When you have the establishment backing you so reluctantly to the point to where you have people endorsing you that said that you would get murdered on the Senate floor and nobody would care and the difference between Donald Trump and Ted Cruz is being stabbed or shot, their loyalty is not with Sen. Cruz,” she said.

Pierson was referring to comments made by Sen. Lindsey GrahamLindsey Olin GrahamCheney unveils Turkey sanctions legislation Overnight Defense — Presented by Boeing — House passes resolution rebuking Trump over Syria | Sparks fly at White House meeting on Syria | Dems say Trump called Pelosi a 'third-rate politician' | Trump, Graham trade jabs War of words at the White House MORE (R-S.C.), a former presidential candidate who backed Cruz last month as the best candidate to take on Trump after a series of negative comments about the Texas senator.

“However, Sen. Cruz has now made himself that Trojan horse to push this to a contested convention, of which where the GOP and the RNC have no intention of supporting either one of them,” Pierson said.

Pierson said that if there is a contested convention, "You will see a lot of the rules changing again."

"Because this is how the establishment blocks the people's choice," she said. "They've admitted it. They're not hiding it."