In fact, should Trump be successful in imposing some of these tax ideas, for instance, a deduction for interest on auto loans and exempting taxes on Social Security income, it would represent a return to some of the tax policies that last existed in the early 1980s, before the Reagan Revolution.

“So this is kind of going back, back, back, way back,” Will McBride, vice president of federal tax policy at the Tax Foundation, told the Washington Examiner. “Actually, a lot of these things that Trump is proposing would actually return the tax code to the way it was before the 1986 tax reform.”

In 1986, President Ronald Reagan shepherded through landmark tax legislation with bipartisan support that simplified the tax code, closed loopholes, and was designed to make the system fairer. It gutted special tax deductions and lowered income and corporate taxes.

Broadening the base has been a goal of Republicans since the Reagan-era tax reform effort. The idea is that special deductions and credits should be limited in the tax code so that there is a larger amount of income being taxed. That larger pool allows for overall rates to be lowered without cutting into revenue.

Broadening the base was top of mind for former House Speaker Paul Ryan who helped get the 2017 Tax Cuts and Jobs Act, better known as the Trump tax cuts, passed. The Trump tax cuts include a number of base-broadening measures, including, notably, a $10,000 cap on deductions on state and local taxes paid. A group of lawmakers in high-tax jurisdictions such as New York and California has been adamant in resisting that provision of the overhaul and seeking its repeal.

But now Trump even appears to be reversing course on the SALT cap, a position that Republicans in many parts of the country have vehemently opposed, given their desire to keep the base-broadening provision. But vulnerable Republicans in high-tax states have pushed for SALT relief, and in a message on social media, Trump said he would “get SALT back.”

Other Trump tax proposals this time around also narrow the tax base instead of broadening it. That is in contrast to others in Trump’s orbit during his first administration, such as Ryan, a budget hawk who was known for frequently invoking the need to broaden the base during the Obama administration while he was chairman of the House Budget Committee.

Trump announced earlier this month that he intends to make interest paid on car loans fully deductible, a proposal he rolled out while in Michigan, which is the country’s auto-manufacturing base.

The rollout was similar to how he announced his plan to end taxes on tips during a visit to service industry-heavy Nevada. That proposal also cuts against a desire to broaden the tax base and an iteration of the plan has since been endorsed by Trump’s opponent, Vice President Kamala Harris.

Trump released another proposal targeted toward a specific subset of the population, in this case seniors, over the summer when he announced that he plans to exempt Social Security income from taxes.

“It is a sharp break from traditional Republican tax orthodoxy over the past couple decades, even leading up to and including the Tax Cuts and Jobs Act, which Trump himself signed into law,” Kyle Pomerleau, a senior fellow at the conservative American Enterprise Institute, told the Washington Examiner.

Stephen Moore, a Heritage Foundation economist and informal adviser to Trump, told the Washington Examiner that it is a truism that the basis for a good tax system is to have a broad tax base and a low tax rate.

“But you know, then the question is, what is the proper base of taxation?” Moore said.

Moore brushed off potential criticism for some of these new Trump tax proposals by pointing out that some of them, like the tipped tax exemption, are “micro tax cuts” that aren’t going to affect the tax base much because they are small.

The Tax Foundation estimates that exempting taxes on tips would cost the U.S. over $100 billion in revenue over the next decade, and his plan to create an itemized deduction for auto loan interest would cost $61 billion — those are pretty small in the grand scheme of things.

But some of Trump’s other proposals that would narrow the tax base would be much bigger.

For instance, his plan to exempt overtime pay from payroll taxes would lose nearly $750 billion in tax revenue over the next decade. Not taxing Social Security income would cost nearly $1.2 trillion.

The possibility of Trump pushing for relief on the $10,000 SALT cap is one that Moore said he hasn’t yet talked to the former president directly about, but he said in his talks with Republicans in high-tax states, he gets the sense that they just want some relief — not a wholesale return to the state and local tax deduction.

“I’m just picking out a number, let’s say you raised it to 20%, so that would provide really for middle-class people who have been hit by the elimination of the salt deduction,” Moore said. “But millionaires and billionaires living in Long Island or Manhattan, they effectively still lose the SALT deduction because the exempted amount is so small relative to their income that it doesn’t matter.”

Fully restoring the deduction on state and local taxes would also be very expensive. It would evaporate $1 trillion in tax revenue over the next decade.

Trump’s proposals all target groups that are critical voting blocs in the elections. For instance, tipped workers in the key battleground state of Nevada would benefit, as would seniors in Arizona and other swing states.

The problem that some of these tax proposals may face in Congress is that they come as the U.S. faces a serious fiscal reckoning. The federal debt is approaching $36 trillion, and payments on interest have skyrocketed. Without major cuts to spending or new revenue-raising proposals, the policies would only make the situation worse.

In a statement provided to the Washington Examiner, Trump campaign national press secretary Karoline Leavitt highlighted how the economy is the No. 1 issue for voters and highlighted Trump’s pledge to continue cutting taxes beyond just the 2017 cuts, much of which are set to expire at the end of next year.

“President Trump is leading poll after poll on the economy because voters know when he returns to the White House, he will work with the House and the Senate to make tax cuts PERMANENT, and once again cut taxes for working families, end taxes on tips for service workers, end taxes on Social Security for our beloved seniors, and end taxes on overtime pay,” she said.

CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER 

Questions about base broadening aside, Moore said that the main tax policy objective for Republicans entering a new Congress is the same as it was a year ago before any of these new tax proposals were floated — making the 2017 Trump tax cuts permanent.

“So then you come to these cats and dogs and some of them probably would be affordable, and some of them may not be,” Moore said of the new Trump proposals from this year.