WASHINGTON — President Trump will take his appeal for tax reform to the nation's truckers on Wednesday with a speech in Harrisburg, Pa.

Truckers and their rigs will be the backdrop as Trump tries to cast his tax plan as a boon to the middle class – even as the nonpartisan Tax Policy Center says those with the very highest incomes would receive the biggest tax cuts.

"Nothing gets done in America without the hardworking men and women of the trucking industry," Trump will say, according to excerpts of the speech released by the White House. "When your trucks are moving, America is growing. 'America first' means putting American truckers first.

Trump has been traveling the country to tout what he calls a "once in a generation" opportunity to simplify the tax code, cut rates and spur economic growth.

But Wednesday's speech will also include a new claim: That the typical American household could see their wages go up by $4,000 from a provision encouraging major U.S. companies to bring back — or repatriate — profits currently stored overseas.

A White House official previewed the speech to reporters Tuesday on condition he not be identified so as not to upstage the president's remarks.

"We will eliminate the penalty on returning future earnings back to the United States. And we will impose a one-time low tax on money currently parked overseas so it can be brought back home to America – where it belongs," Trump says in the speech.

The White House didn't provide evidence to support the $4,000 claim, but it echoes one made by a White House economist last week. Kevin Hassett, chairman of the White House Council of Economic Advisers, said the typical household could see an additional 1% wage growth under the president's plan — which would total $4,000 over eight years.

Hassett said last week that worker pay is not keeping pace with corporate profits because much of those profits are parked overseas to avoid higher U.S. tax rates.

“Workers used to get a 1.1 percent raise for a 1 percent increase in corporate profits. Now the pass-through to workers is closer to 0.4 percent. Why did it change so much? Because the profits are offshore, benefiting other nations’ workers,” said Hassett. Offering a onetime low tax rate to bring back those profits would help close that gap, he said.

Hassett's chief of staff, D.J. Nordquist, said the CEA would produce a white paper soon backing up those numbers with a detailed analysis.

Trump often speaks about bringing back trillions of dollars that U.S. companies are believed to keep overseas, and has floated a one-time low tax rate on those corporate profits.

In a Forbes interview released this week, Trump said he believes his tax plan will lower the deficit. "This is going to bring $3 trillion dollars back," he said, noting that "the offshore money" will help achieve this goal.

While Trump hasn't provided details of his plan, the principle isn't much different from that of President Barack Obama. Obama proposed a one-time repatriation rate of 14% to encourage global companies to bring profits back to the United States. After that, they would be subject to a 19% rate — but with credits for foreign taxes paid.

But those ideas may seem distant to the working-class taxpayers Trump will address in an Air National Guard hangar in Harrisburg. The crowd will include about 1,000 workers organized by the Pennsylvania Manufacturing Association, the Pennsylvania Chamber of Commerce and other business groups, the White House said.

Trump is appealing not just to drivers, but to owners of small, family owned trucking companies. One proposal, repealing the estate tax would help pass those businesses from one generation to the next.

That tax is charged on estates worth about $5.5 million or more. According to the Tax Policy Center, only about 50 small business and small farm estates nationwide will face any estate tax in 2017, owing on average less than 6% of their value in tax. The provision also brings in significant revenue to the federal Treasury.

The group also estimates that, under the plan “in 2018, all income groups would see their average taxes fall, but some taxpayers in each group would face tax increases.”

The Trump administration is also facing broader questions about how it will fund the tax plan. The nonpartisan Committee for a Responsible Federal Budget estimates the plan calls for roughly $2.2 trillion of net tax cuts.

Trump is seeking to build momentum for a tax plan already under criticism from Democrats who say it will explode the deficit in exchange for repealing the estate tax and maintaining preferential tax rates for some of the wealthiest Americans, including hedge-fund managers.