A panel of Washington, D.C. tax experts ripped apart the 2016 Republican field's tax proposals, saying that only with "magical thinking" could their plans to lower taxes work from a budget perspective.
"There's just a lot of magical thinking going on on the Republican side," said Len Burman, the director of the Tax Policy Center, a joint venture of the Urban Institute and the Brookings Institution. "The biggest tax cut, Donald Trump's, it actually ruled out the biggest area to cut spending, which is on the mandatory side."
Businessman and front-runner Donald Trump's plan also increases tax incentives for businesses by the highest degree of any candidate.
"The biggest loophole — it kind of sounds like a reality television program — goes to Donald Trump, who would have a 15 percent tax rate on businesses income and a 25 percent tax rate on other income, which would encourage almost everybody in this room to become a business," Burman said.
According to Trump's website, no business of any size, "from a Fortune 500 to a mom and pop shop to a freelancer living job to job," will pay above 15 percent of their business income in taxes.
"This lower rate makes corporate inversions unnecessary by making America’s tax rate one of the best in the world," he says on his website.
But as was pointed out by Fox News debate moderators earlier this month, the tax experts agreed that Trump's plans to cut the federal deficit while lowering taxes don't add up.
The Committee for a Responsible Federal Budget, which held the panel event on Thursday on Capitol Hill, estimated that in order to pay for Trump's tax and other plans by making cuts outside of Social Security, Medicare and the Department of Defense — areas he's marked as off-limits — would require cutting the rest of the federal budget by between 61 percent and 78 percent.
And balancing the budget under Trump's plan as written is entirely impossible, said CRFB, which is chaired by former Republican Indiana Gov. Mitch Daniels, former Defense Secretary Leon Panetta and former Rep. Tim Penny from Minnesota's Democratic–Farmer–Labor Party.
The three leading Republicans' tax-cut plans would all lead to a sizable revenue decrease — Cruz's would reduce revenue by $8.7 trillion between 2017 and 2026, Sen. Marco Rubio's would reduce it by $6.8 trillion in those same 10 years and Trump's would reduce revenues by $9.5 trillion, according to CRFB.
To get a sense of scale, $9.5 trillion is 4 percent of the gross domestic product.
In fact, no GOP tax proposal includes enough information about how the candidates plan to offset the revenue decreases.
"While the candidates have touted their planned tax cuts, they have provided little or no detail on how they would make up the lost revenue," the CRFB concluded in its report. "Given the sheer size of our projected deficits, this means that the tax cut proposals would, if enacted, inevitably force draconian spending cuts and/or substantial tax increases.
"In other words, a tax cut paid for with borrowed money now inevitably will lead to big tax increases and/or huge program cuts later."
[sharequote="center"]"What they're promising doesn't match up on the spending side." - Kyle Pomerleau, Director of Federal Projects, The Tax Foundation[/sharequote]
Bob McIntyre, the director of progressive tax research group Citizens for Tax Justice, said that Texas Sen. Ted Cruz's plans are so unheard of that they're difficult to estimate.
For example, in Cruz's stump speech he says that he'll abolish the IRS on his first day in office. He also says that under his tax system, every American will be able to fill out their taxes on a "postcard." Cruz's plan would also require significant spending cuts or incredibly high rates of GDP growth to break even, according to CRFB.
McIntyre said for his estimates of the plan's cost, he assumed that Cruz would only actually rename the IRS — not abolish it.
The good news, Burman said, is that the U.S. doesn't need a good tax system to grow, "or we would have been in a depression for the past 20 years."
Republicans aren't the only ones whose plans don't fully add up. Vermont Sen. Bernie Sanders, who's been outspoken about his plans to raise taxes in order to fund a single-payer or Medicare-for-All health care system, only proposes offsets to cover three-quarters of that program's cost, according to estimates from CRFB.
"Bernie Sanders proposes a big tax increase," Berman said. "He argues that government would provide a lot more services, and he would be willing to pay for them."
But his current offset plans would lead to a $2.6 trillion to $2.8 trillion shortfall over ten years, the CRFB estimates said.
Democratic front-runner Hillary Clinton's plan is "basically a continuation of the status quo," Burman said.
Most of Clinton's planned tax increases focus on the moderately to very wealthy — her plan follows the Buffet Rule, which would impose a 30-percent minimum income tax rate on U.S. citizens making more than $1 million. It also closes loopholes that allow high earners to claim certain tax deductions or classify income as capital gains to avoid paying taxes.
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