Advisers to President Donald Trump are reportedly working on a plan to slash the "middle class" tax rate to 15 percent, a pre-election effort that tax experts and progressive critics slammed as an admission that the first round of Republican tax cuts did nothing for most Americans while further enriching the wealthiest.

"Here we go again," Americans for Tax Fairness executive director Frank Clemente said in a statement Tuesday, pointing out that the 2017 GOP tax law was also sold as a "middle class tax cut."

"Raising the idea of a new 'middle class tax cut' is an admission by the president that his first tax cut was a scam. It wasn't aimed at the middle class but aimed at his wealthy friends and big corporations."

—Frank Clemente, Americans for Tax Fairness

"What's the line, fool me once…? A vague, election-year promise of a huge tax cut for the middle-class should be viewed very skeptically," said Clemente. "Raising the idea of a new 'middle class tax cut' is an admission by the president that his first tax cut was a scam. It wasn't aimed at the middle class but aimed at his wealthy friends and big corporations. Why should we expect anything different now?"

The Washington Post reported Tuesday that a team of Trump aides led by National Economic Council director and Wall Street ally Larry Kudlow is exploring a number of proposals that would further cut taxes, including some that would disproportionately reward the rich.

The plan under consideration would likely aim to cut the tax rate for those who earn between $30,000 and $100,000 to 15 percent. The Post notes that the "current marginal tax rate for someone making $90,000 is 24 percent."

Such a tax cut, according to the Post, "would give tax relief to the middle class and the rich, since the rich also pay marginal taxes on the lower rates."

Michael Linden, a tax expert at the Roosevelt Institute, said "depending on where it starts, a 15 percent rate would be a relatively small tax cut for middle income people."

"This is an acknowledgement that Republicans' original tax plan was heavily skewed to the wealthy, the middle got almost nothing, and people at the bottom got literally nothing," said Linden. "I'm not sure having a second go at it is going to solve anything."

Just for context here, a single filer making $50,000 would receive a tax cut of $0. A married couple making $100,000 would receive a tax cut of $0. https://t.co/0UftCRxVqt — Michael Linden (@MichaelSLinden) November 12, 2019

Stephen Moore, a right-wing Heritage Foundation economist who has worked with the Trump White House on tax policy, is "also pushing for a change that would allow capital gains to 'roll-over' tax-free if they are reinvested in a different stock," the Post reported.

In response to Moore's proposal, Post columnist Catherine Rampell warned on Twitter, "Don't be fooled."

"That 'middle-class tax cut' the Trump administration is floating is actually a Trojan Horse designed to effectively eliminate capital gains taxes for the rich," said Rampell.