Here's an amazing fact: Ryan's tax reform plan costs more than all his spending cuts combined.

So how will he pay for his much, much lower rates? Well, he doesn't say. In fact, he doesn't even begin to say. His budget doesn't name even one tax deduction, exclusion, credit, or loophole that will be closed. All he says is that he will pay for his lower rates, or at least the House Ways and Means Committee, which is in charge of writing any tax reform bill, will pay for them.

But he doesn't say that they'll pay for them while keeping the tax code as progressive as it is today.

Ryan's budget is very clear in its instructions to the House Ways and Means Committee. They can only submit a tax reform bill that "simplifies the tax code to make it fairer to American families and businesses and reduces the amount of time and resources necessary to comply with tax laws," "substantially lowers tax rates for individuals," "repeals the alternative minimum tax," "reduces the corporate rate to 25 percent," "transitions the tax code to a more competitive system of international taxation," and is "revenue-neutral".

Nowhere does it say the final bill needs to retain the current progressivity of the code.

That's likely because it would be impossible to enact the kind of reform Ryan's previewing while retaining the progressivity of the tax code.

You've watched this debate play out before. During the election, Mitt Romney had an ambitious tax reform plan, a promise to pay for it, and no details. So the Tax Policy Center undertook an incredibly generous analysis in which they assumed that Romney would wipe out every single deduction for the rich before touching any tax breaks for the non-rich. It still wasn't enough. And Ryan's plan, as the Center on Budget and Policy Priorities notes, would be even tougher to balance:

Even with the same dramatic scaling back of tax expenditures for filers with incomes above $200,000 that TPC examined in its Romney analysis — including entirely wiping out their deductions for mortgage interest and charitable giving — families with children that have incomes below $200,000 would have to face tax increases averaging more than $3,000 a year, if policymakers were to avoid increasing the deficit while reaching Chairman Ryan’s 25-percent top-tax-rate goal.

Now, Ryan has a bit of wiggle room here. As mentioned above, any tax reform that qualifies for his budget "substantially lowers rates for individuals," but it doesn't necessarily lower them all the way to 10 percent and 25 percent. That's just "a goal." Here's the full section:

Substantially lowers tax rates for individuals, with a goal of achieving a top individual rate of 25 percent and consolidating the current seven individual income tax brackets into two brackets with a first bracket of 10 percent

Compare that to the language on corporate taxes:

reduces the corporate tax rate to 25 percent

See the difference?

Ways and Means could, in theory, decide the 10/25 goal is too hard to meet, and their tax reform bill will end with a 20 percent rate and a 32 percent rate. That would be considerably easier to pay for. But Ryan is in touch with Rep. Dave Camp, the chairman of the House Ways and Means Committee. It's unlikely he's committing Republicans to goals that Camp doesn't intend to come anywhere near reaching. And if Ryan and the Republican Party wanted to assure the country that their tax reform proposal would keep the code's current progressivity, they could have said so.

The critique right now of Ryan's tax reforms is that they're a huge tax cut for everybody. As I wrote on Friday, I don't think that's a fair read of what he's promised. Rather, the eventual tax reforms are likely to include a significant tax increase on many Americans, and significant tax cuts for those at the very top.