Sen. Ron Wyden (D-OR) on Thursday blasted President Donald Trump's treasury secretary, Steve Mnuchin, for using dubious economic projections to sell a tax cut plan that will largely benefit the wealthiest Americans.

"It certainly isn't a tax recipe focused on the middle class," Wyden explained in a speech on the Senate floor. "The treasury secretary doubled down on the failed experiment that tax cuts pay for themselves. Forget the history that says that isn't true. The Trump treasury secretary said that the tax cuts won't just pay for themselves, they'll raise an additional trillion dollars in revenue on top of their own costs."

"The fact is, Mr. President, there is no magical growth fairy, no unicorns, no kind of growth fairies that are going to somehow spring to life if this tax cut plan becomes law," the Oregon Democrat charged. "But our secretary, Treasury Secretary Mnuchin, keeps going back to the unicorns, keeps going back to rainbow economics."

Wyden noted that Republican economists have admitted to the finance committee that tax cuts do not pay for themselves.

According to Wyden, Mnuchin is guilty of telling other "whoppers" to sell Trump's tax plan.

"Mnuchin said, 'It's very hard not to give tax cuts to the wealthy with tax cuts to the middle class," Wyden observed. "That is one stunner of a statement."