Donald Trump speaks at the Republican party of Iowa's Lincoln Dinner in Des Moines in May. (Jim Young/Reuters)

Helicopter aficionado and Park Avenue resident Donald Trump said Monday morning that the rich should pay more in taxes than the middle and working classes.

He criticized the idea of taxing all Americans at the same rate, an idea endorsed by some of his rivals for the GOP presidential nod. Sen. Rand Paul (R-Ky.) has proposed levying the same tax on all forms of income and on businesses, which would be able to write off their expenses under his plan. Mike Huckabee, the former governor of Arkansas, has called for taxing sales instead of income, but also at a single rate. Other Republican plans, such as the one put forward by Sen. Marco Rubio (R-Fla.), have more than one rate, but fewer than the seven brackets in the current system.

Getting rid of the separate, higher tax rates for the wealthy would allow them to pay less in taxes on additional income, which proponents say would encourage them to work and contribute to the economy. A tax system with fewer brackets would also be simpler.

Simplifying the tax code is a goal that Trump said he shares, but he also believes that rich Americans should pay more on every dollar of additional income.

"The one problem I have with a flat tax is that rich people are paying the same as people that are making very little money," Trump, who is worth an estimated $2.9 billion, said Monday morning on "Fox & Friends." "I think there should be a graduation of some kind."

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The Republican front-runner also advocated higher taxes on hedge-fund managers, a position shared by his Democratic opponent Hillary Rodham Clinton.

Managers at hedge funds are able to count their income as returns on investments, allowing them to pay less in taxes than they would if they reported their earnings as a salary or a wage. It's known as the carried-interest loophole, and while it's difficult to know how much it costs the government, one estimate puts the price tag at a whopping $180 billion over 10 years.

Clinton said she'd close the loophole, and while Trump didn't mention carried interest specifically, he did say that hedge-fund managers should pay more in taxes.

"They should be taxed a fair amount of money," he said, without offering details. "They're not paying enough tax."

He later criticized Clinton as being too close to Wall Street.

"The hedge-fund guys are the ones that are giving her the money," he said. "When she was in the Hamptons, she was with the hedge-fund guys."

Trump also contrasted managing a hedge fund with his own field, real estate. "It's one thing if you're building buildings," he said. "If you build buildings, you put people to work. These hedge-fund guys, they move around papers."

Recently, Trump has been involved in very little actual building, as The Washington Post has reported. Much of his income comes from simply signing his name on various deals around the world. Other investors pay him for the right to use his name in connection with their projects.

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