Data indicating that Americans are getting smaller tax refunds this year has triggered fresh criticism of the 2017 tax overhaul engineered by congressional Republicans.

Early reports from the IRS show the average refund is 8.7 percent smaller than the same period last year. The Treasury Department said initial news reports on the refund statistics were “misleading” and said taxpayers having smaller refunds means that their tax withholding throughout the year was more accurate.

That hasn’t stopped many Democrats, including some potential 2020 presidential candidates, from renewing claims that the GOP’s Tax Cuts and Jobs Act (TCJA) disproportionately favors corporations and millionaires over the middle class.

Sen. Sherrod Brown (D-OH) is pushing legislation to double the Earned Income Tax Credit for working families and told an audience in Ohio this week that “more and more Americans are filing their tax returns and getting their tax refunds, and they realize that the president’s tax law was a bit of a sham.”

Republican tax-writers are defending the tax law by pointing to the strong economy and low unemployment rate, and by explaining that a smaller refund is not a sign that Americans are paying more taxes.

“The size of your tax refund has nothing to do with your overall tax bill. It merely reflects what you overpaid the IRS in your paychecks last year,” said Rep. Kevin Brady (R-TX), the ranking member of the House Ways and Means Committee who helped draft the tax law passed by Congress in 2017. “For most Americans, the Tax Cuts and Jobs Act delivered larger paychecks starting last February, even if many workers didn’t notice…Since many workers and families live paycheck-to-paycheck, getting at least some of their tax cut in advance, rather than delaying it a year, is a life saver.”

Having retaken the House in last fall’s midterm elections, Democrats are intent on making some changes to the tax law to help the middle class, including expanding the EITC and the child tax credit. Some Democrats also want to repeal the tax law’s $10,000 cap on deductions for state and local taxes, which they say is hitting households hard in high-tax states like New York, California, Connecticut and New Jersey.