President Donald Trump pledged to eliminate "tax breaks and loopholes" that favor the highest earners.
One of the tax breaks in the administration's crosshairs would also target Democrats, according to a CNBC analysis.
In a speech in Indianapolis Wednesday, Trump offered broad outlines of the administration's long-awaited tax reform package. But it was short on details on which of the dozens of lucrative tax breaks in the current tax code may be eliminated.
But at a Tuesday briefing ahead of Wednesday's formal announcement, a senior White House official signaled that a popular deduction for taxes paid to state and local governments will be eliminated. Doing so would hit Democratic voters hardest, according to IRS data.
The provision at risk is a long-standing rule that lets you deduct from your reported income the money you pay in state and local taxes on income, real estate or sales of big-ticket items.