The poorest Americans are subject to a tax rate at the state and local level that is twice as high as the tax rate paid by the wealthiest earners thanks to “fundamentally unfair” state tax laws, according to a new report from the Institute on Taxation and Economic Policy (ITEP). Middle-class taxpayers also pay higher effective rates than the wealthy.

When state, local, property, and sales taxes are taken into account, the poorest 20 percent of Americans pay an average effective tax rate of 11.1 percent, the report found. The middle 20 percent pays a 9.4 percent rate, while the rate for the top 1 percent is just 5.6 percent. The lack of progressive income taxes and an over-reliance on consumption taxes are the primary culprit, the report says.

In the 10 most regressive states, the poorest 20 percent pay a rate as much as six times as high as the rate for the richest 1 percent. Four of those states — Washington, Texas, Florida, and South Dakota — have no income tax; one, Tennessee, has a limited income tax that only applies to dividends and interest. In these five states, half to two-thirds of revenue comes from sales and excise taxes, well above the national average of one-third.

Still, Republicans across the country are pushing tax plans that would replace income taxes — typically the only form of progressive taxation at the state level — with sales taxes. Republicans in Nebraska, Kansas, North Carolina, and Louisiana have advanced such plans, even though their state tax systems are already regressive.

In Louisiana, worst of the four, the poorest 20 percent pay 9.2 percent of their income in sales taxes, while the wealthiest 1 percent pay just 1.3 percent. Even in North Carolina, the best of the four, the poor pay six times as much of their income in sales taxes as the richest one percent. Shifting to a tax code that relies solely on sales taxes would make these states even worse.

Nebraska Gov. Dave Heineman (R) became the latest Republican governor to propose the elimination of his state’s income tax during his State of the State speech last night, a move that would eliminate $2.4 billion in revenues each year. To replace the lost revenue, Heineman proposed eliminating at least half of the $5 billion in sales tax exemptions Nebraska offers annually, but he did not specify which of those exemptions he wanted to eliminate, KearneyHub.com reports:

“This about the future of Nebraska,” Heineman told state lawmakers. “Nebraska has good schools, affordable homes, a strong work ethic and a low unemployment rate, but taxes are too high.” [...]

He had been promising for weeks to deliver a “bold” tax plan during his address. He outlined a bold vision, to be sure, but didn’t include the rest of the story — exactly how the state would shift taxes to offset the $2.4 billion now collected in state income taxes.

Louisiana Gov. Bobby Jindal (R) and Republicans in North Carolina have also proposed replacing income taxes with increased sales taxes in their states, a move that would result in a tax cut for businesses and the wealthy while raising taxes on the poor. Jindal’s plan would give the top one percent of Louisiana residents a 2.3 percent tax cut while raising taxes on the bottom 80 percent. The poorest 20 percent would see a 3.4 percent increase.

Though the details of Heineman’s plan are still unclear, it is hard to imagine the poor not picking up the burden, since sales taxes are inherently regressive. The poorest 20 percent of Nebraskans already pay 6.4 percent of their income in sales taxes, according to the Institute on Taxation and Economic Policy. The top one percent pays just 0.8 percent. The poorest fifth of Nebraskans pay 11.1 percent of their income in taxes overall, compared to just 7.1 percent for the richest one percent. Heineman has ruled out ending sales tax exemptions on groceries, but other exemptions, such as those for hospital beds, dorm rooms, and other medical costs would level a direct hit on the state’s poor and middle-class residents.