Sen. Marco Rubio when he was a presidential candidate. (Jacquelyn Martin/AP)

Democrats frequently claim Republicans' corporate tax cuts enriched big businesses while doing little for workers, but now that line of criticism is coming from a prominent Republican: Sen. Marco Rubio.

“There is still a lot of thinking on the right that if big corporations are happy, they’re going to take the money they’re saving and reinvest it in American workers,” the Florida senator told the Economist in a recent interview. “In fact they bought back shares, a few gave out bonuses; there’s no evidence whatsoever that the money’s been massively poured back into the American worker.”

The GOP tax law dramatically reduced taxes on American businesses, cutting the corporate tax rate from 35 percent to 21 percent. The White House said throughout the tax debate that the law's corporate cuts would increase wages for the average American worker by $4,000, a claim made by White House spokeswoman Sarah Huckabee Sanders and Kevin Hassett, chairman of the Council of Economic Advisers.

Nonpartisan experts were skeptical about the claim, and independent analyses say the bulk of the law's tax cuts would go to the wealthy.

The remark was seized on by Senate Democrats, with the office of Senate Minority Leader Charles E. Schumer (D-N.Y.) broadcasting it on Monday.

“We couldn’t have said it any better ourselves,” wrote Schumer spokesman Matt House.

In a statement on Monday, Rubio spokeswoman Olivia Perez-Cubas said that the senator believes the corporate tax cut would make the U.S. more competitive for companies, but did not say it will lead to the kind of wage growth for workers touted by other Republicans.

“Rubio pushed for a better balance in the tax law between tax cuts for big businesses and families, as he’s done for years,” Perez-Cubas in an email. “As he said when the tax law passed, cutting the corporate tax rate will make America a more competitive place to do business, but he tried to balance that with an even larger child tax credit for working Americans.”

But conservative organizations were quick to condemn Rubio for appearing to take the Democratic line on tax reform.

“It’s disappointing to see Marco Rubio echo some of the false rhetoric of tax reform opponents, and we hope he clarifies his remarks,” said Brent Gardner, chief government affairs officer for Americans for Prosperity, the conservative political advocacy group tied to the billionaire industrialists Charles and David Koch. “There’s no doubt that the full potential of tax reform will be realized over the long-term, but there’s also no denying the positive impact it’s already having on American workers, businesses and families across the country.”

This is not the first time Rubio expressed skepticism about the possible benefits of the corporate tax cut, arguing before the passage of the bill that the tax package had to do more to protect lower-income families. He announced his opposition to the Senate package days before a vote, calling for an expansion of a tax credit for children that would have primarily helped poor and middle class families.

Rubio voted for the bill after a diminished version of his proposed tax credit was included in the law's final text.

In the interview with the Economist, Rubio pitched a set of government programs and policies aimed at helping workers. He argued for a more generous benefit system and paid-family-leave program, as he also touted the more robust child tax credit he pushed during the GOP tax debate. He also advocated expanding training programs for new workers and workers who've lost their jobs.

“Government has an essential role to play in buffering this transition,” he said. “If we basically say everyone is on their own and the market’s going to take care of it, we will rip the country apart, because millions of good hard-working people lack the means to adapt.”