Having crunched the numbers on the tax plans of Republican presidential candidates Jeb Bush, Donald Trump, and Marco Rubio, the Tax Policy Center — one of the only nonpartisan economic think tanks respected on both sides of the aisle in Washington, DC — is out with an analysis of Iowa victor Ted Cruz's tax plan.

Cruz's plan is a more transformative overhaul of the federal tax code than any of those three candidates' proposals, even Rubio's. Cruz would replace the individual income tax with a 10 percent flat tax; abolish all payroll taxes, the corporate tax, the estate and gift taxes, and the alternative minimum tax; and impose a 19 percent value-added tax, a kind of sales tax.

He'd also increase the standard deduction significantly, add a new $25,000 deduction for savings for any purpose, and eliminate all other deductions save the mortgage interest and charitable ones. He'd tax capital gains as normal income, but at 10 percent, which is still way below the current 23.8 percent top rate.

TPC finds that the plan would cost more than Bush or Rubio's proposals but somewhat less than Trump's. Including both lost revenue and interest, Cruz's plan would cost $10.2 trillion over 10 years. Bush's costs $8.1 trillion, Rubio's $8.2 trillion, and Trump's $11.2 trillion. In its first decade, Cruz's plan would increase the debt by 35.7 percent of GDP; over two decades, that figure rises to 68.7. The current level is about 75 percent of GDP, so Cruz would spike it dramatically.

And even more than his rival's plans, Cruz's concentrates its benefits heavily among the richest Americans:

The Cruz plan would save the lowest fifth of taxpayers only $46, or 0.4 percent, on average. By contrast, the top 0.1 percent would get nearly $2 million back, or 29 percent. And that's only in 2017. By 2025, the poorest fifth of Americans are actually paying more on average — $116 each, to be precise. The VAT would impose a double burden on the poorest Americans, both raising the cost of goods and reducing wages (because they wouldn't be deductible the way they are with a corporate income tax).

The overwhelming majority of the plan's cost (79.6 percent) goes to helping the richest fifth of taxpayers; 43.7 percent goes to the top 1 percent alone.

Overall, it's the biggest giveaway to the rich that any top GOP contender is offering:

Cruz moves the tax code away from income and toward consumption

Cruz's proposal isn't a pure consumption tax. The VAT is, but the income tax still affects investment income, meaning there's still a savings disincentive. But it's much, much, much lower — not least because of the new $25,000 deduction for savings. "Senator Cruz’s proposal would exempt most saving from tax since only a tiny fraction of households have more than $25,000 in annual savings," TPC notes.

Many economists think taxing consumption is better for economic growth than taxing income, as it encourages savings and investment. But this view isn't universal. The recent research finding that tax incentives to save don't promote savings particularly well and the fact that the 2003 tax cut in dividends didn't really boost the economy have also cast doubt on the general case for consumption taxation.

But the thing is, taxes on savings are already very low for most Americans. Many — those in the 20th through 60th percentiles of taxpayers, income-wise — would actually face higher tax rates on capital gains and dividends under Cruz's proposal. The really big cuts are for the top 1 percent:

The sheer cost of Cruz's plan is also worth dwelling on. If unpaid for, it increases the deficit by more than $1 trillion a year, and would require about $860 billion a year in spending cuts to avoid that. And Cruz has said he wants to balance the budget, so spending cuts are how the plan would have to be paid for if he keeps that promise.

Those are truly epic spending cuts. Again, Cruz needs $860 billion less spending every year. By comparison, eliminating Medicaid entirely would only save about $500 billion a year. Eliminating Obama's subsidies would only save $92.5 billion.

In fact, you could eliminate both of those, plus the Children's Health Insurance Program, plus food stamps, plus Supplemental Security Income (which helps desperately poor old and disabled people), plus all federal unemployment compensation, plus Temporary Assistance for Needy Families (TANF, or welfare), and still not be able to pay for all of Cruz's tax cuts. You could eliminate all non-defense discretionary spending — stuff like funding for the FBI and other federal law enforcement, Head Start, the National Institutes of Health, the Centers for Disease Control and Prevention, etc. — and it wouldn't come close to paying for Cruz's plan.

Realistically, Cruz would pay for this by exploding the deficit. But it's worth taking him at his word and considering what paying for it by cutting spending means. His campaign insists it can be done by merely cutting waste and unnecessary bureaucracy. That's a fantasy. It will almost certainly require cutting either vital public services or huge parts of the safety net for the poor. And when that's taken into account, most Americans won't feel richer at all.

Correction: This post originally stated that the debt was around 100 percent of GDP. It's more like 75 percent if you exclude debt held by the government itself.