Rand Paul has perhaps the most extensively documented national policy positions of any 2016 contender. He is the only candidate in the race to have prepared his own detailed federal budget — three times, in fact, in fiscal years 2012, 2013, and 2014. The budgets, put together, represent the most radical vision of limited government ever presented by a major American presidential candidate (apart, perhaps, from Paul's father, Ron Paul).

A lot of material in the budgets is standard Republican fare. Paul wants to partially privatize Social Security, increase the retirement age, and cut benefits for upper-middle-class earners — all things George W. Bush fought for. He would privatize Medicare and block-grant Medicaid and food stamps, all staples in Paul Ryan's budgets.

The gap between Rand Paul's budget and Paul Ryan's is nearly as big as the gap between Ryan's and Democrats'

But he doesn't stop there. At various points in the budgets, Paul questions the constitutionality of progressive income taxes, eliminates almost all federal education and housing programs, ends the biggest anti-poverty tax credits, eliminates foreign aid, institutes large defense cuts, slashes the State Department budget by more than two-thirds, and cuts the Food and Drug Administration budget to limit government "intrusion into the nation’s food supply." It's the most detailed expression of what a libertarian approach to budgeting would look like to date, with Paul specifying even the tiniest agencies he wants to do away with (goodbye, Government Printing Office!).

If implemented, these proposals would result in a dramatically smaller federal government. According to the Committee for a Responsible Federal Budget, Paul's FY2014 budget would reduce spending to 16.4 percent of GDP by 2023. By contrast, Paul Ryan's budget would reduce spending to 19.1 percent of GDP, and Senate Democrats' budget would keep it at 21.9 percent. The gap between Paul's budget and Ryan's is nearly as big as the gap between Ryan's and Democrats'.

Here are some of the biggest changes in Paul's budget that even his Republican colleagues don't share.

1) A flat tax — by constitutional necessity

The proposal: Paul proposes replacing the personal income tax with a 17 percent flat tax, and suggests that the 16th Amendment forbids the income tax from "redistributing wealth."

Which budget(s): Fiscal years 2013 and 2014.

Details: Paul would repeal the estate and gift taxes, individual capital gains and dividend taxes, and the Alternative Minimum Tax. In place of the existing individual and corporate income taxes, he would implement a version of the flat tax proposal originated by Robert Hall and Alvin Rabushka: a flat tax on wages, and another flat percent tax on the corporations (specifically on their revenue less investments, input costs, and wages). He'd eliminate all tax deductions except the one for the mortgage interest and create a generous standard deduction. While in the FY2013 budget he specifies the rate (17 percent) and deduction size ($32,320 for married couples filing jointly, plus $6,530 per dependent), he left those details out of the next year's budget.

Paul offers a variety of defenses of this idea. The budgets cite the fact that the flat tax is a kind of consumption tax, which many economists believe promotes economic growth. They also note that a flat tax could be filed on a postcard and argues it would reduce the cost of tax compliance.

But at other points, Paul's budgets suggest that a progressive tax is unethical. Part of the point of the tax, according to the FY2013 budget, is "making the system more efficient and fair by broadening the tax base, letting everyone contribute to their government instead of a minority of people contributing for everyone"; the budget goes on to disapprovingly note the fact that "today, the top 10 percent pays nearly 71 percent of all income taxes" while "the bottom 50 percent contributes 2.25 percent and many in this category have a negative tax liability."

The FY2014 budget goes further, invoking constitutional concerns. "The 16th Amendment it makes it quite clear that its intent is to allow the federal government to collect taxes to fund operations and services provided by the federal government," the budget reads. "The amendment does not suggest, however, that the government shall collect taxes, distribute welfare, redistribute wealth, and distort the allocation of resources — yet this is exactly what our tax code does." The current tax code does this, according to the budget, through tax breaks like the Earned Income Tax Credit (EITC) and the Child Tax Credit (CTC), as well as through its progressive structure ("The government also distorts resource allocation by relying on a minority of taxpayers to fund the activities of the federal government.")

These objections raise the question of why Paul allows for a standard deduction, which serves to make a flat tax mildly progressive. In the FY2013 budget, he writes that progressivity makes the flat tax "consistent with the progressive ideology implemented today"; it's unclear whether he thinks this is actively desirable, or a necessary compromise.

In response to a request for comment, Paul spokesperson Jillian Lane emailed, "Sen. Paul has always said we need to scrap the current tax code and replace it with something flatter, fairer, and that leaves more money in the hands of all Americans."

2) Cutting the CDC 20 percent because of its furniture

The proposal: Paul calls for a huge number of specific discretionary spending cuts, including to things like the Centers for Disease Control and Prevention and the National Institutes of Health.

Which budget(s): FY2012 and FY2013, primarily, but also FY2014.

Details: Most spending-cut-heavy budgets, like Paul Ryan's, leave most specific discretionary cuts unspecified. Not Rand Paul's. His FY2012 and FY2013 budgets call for a 20 percent cut for the Centers for Disease Control and Prevention.

"The center is often mentioned in media reports highlighting their lavish accommodations," according to both budgets. "For example, in 2005, the CDC built a conference center for $106 million, complete with large-screen plasma TVs. They also spent tens of millions of dollars on state-of-the-art anti-gravity seating for employees, as well as luxury furniture. Taxpayers can no longer afford the luxury working atmosphere of the CDC."

Here are a few other specific agencies that are also on the chopping block in Paul's budgets, just to give you a sense of how granular he gets:

National Institutes of Health is cut by 20 percent ("much of the research and development undertaken by the NIH provides direct subsidies to the pharmaceutical industry").

is cut by ("much of the research and development undertaken by the NIH provides direct subsidies to the pharmaceutical industry"). Food and Drug Administration is cut by 20 percent ("new FDA powers granted by the recent Food Safety Modernization Act grant the government further intrusion into the nation’s food supply").

is cut by ("new FDA powers granted by the recent Food Safety Modernization Act grant the government further intrusion into the nation’s food supply"). NASA is cut by 25 percent ("with the presence of private industries involved in space exploration and space tourism, it is time for NASA to look at ways to reduce spending … since President Obama has determined to realign the goals of NASA away from human space exploration to science and 'global warming' research, there is also a need to realign the agency’s funding").

is cut by ("with the presence of private industries involved in space exploration and space tourism, it is time for NASA to look at ways to reduce spending … since President Obama has determined to realign the goals of NASA away from human space exploration to science and 'global warming' research, there is also a need to realign the agency’s funding"). US Geological Survey is cut by 20 percent ("though these are important activities, they can be given to state researchers at our colleges and universities").

is cut by ("though these are important activities, they can be given to state researchers at our colleges and universities"). Bureau of Reclamation is eliminated ("owning a majority block of energy and water resources is not the business of the federal government").

("owning a majority block of energy and water resources is not the business of the federal government"). Bureau of Indian Affairs is eliminated ("swindled and mismanaged billions of dollars in Indian trust funds").

("swindled and mismanaged billions of dollars in Indian trust funds"). National Parks are cut by 30 percent ("returning these public lands back to the states and or the private sector would allow an increase in quality, safety and a reduction in government spending each year").

are cut by ("returning these public lands back to the states and or the private sector would allow an increase in quality, safety and a reduction in government spending each year"). Indian Health Services is cut by 20 percent ("notoriously wrought with fraud").

is cut by ("notoriously wrought with fraud"). Government Printing Office is eliminated ("every government office and agency should budget for their own printing costs").

All told, CRFB finds that the FY2012 Paul budget massively reduces the budgets of numerous Cabinet departments:

National Science Foundation is cut by 62 percent .

is cut by . State Department is cut by 71 percent .

is cut by . Interior Department cut by 78 percent .

cut by . Department of Energy is eliminated (except for nuclear energy programs, which are transferred to the Defense Department).

is (except for nuclear energy programs, which are transferred to the Defense Department). General Services Administration is cut by 85 percent .

is cut by . Transportation Department is cut by 49 percent .

is cut by . Department of Agriculture is cut by 49 percent .

is cut by . Department of Health and Human Services is cut by 26 percent .

is cut by . Justice Department is cut by 28 percent .

is cut by . Environmental Protection Agency is cut by 29 percent.

The list goes on. Paul's budget is heavy on massive cuts to discretionary spending and departmental functions. Some of them are mentioned only in early budgets (like the CDC and NIH cuts), but many — including the NASA, US Geological Survey, and National Parks cuts — are also in the FY2014 budget.

3) Eliminating Section 8 housing vouchers and K-12 education funding

The proposal: Paul calls for the elimination of the Housing and Urban Development and Education departments; he singles out Pell Grants as the one program that should remain.

Which budget(s): All three.

Details: The two biggest cuts in Paul's FY2012 budget, according to numbers posted by CRFB, are his elimination of the Department of Education (except for the Pell Grant program, which is rolled back to FY2008 levels and indexed to inflation) and the Department of Housing and Urban Development (HUD). The former amounts to an 83 percent cut to federal education spending, or $78 billion per year. The latter cuts $53.1 billion a year.

This proposal — repeated in the FY2013 and FY2014 budgets, as well — effectively eliminates a wide range of programs. Title I grants and IDEA grants for special education would be gone, removing two major sources of funding for K-12 schools. The Department of Education also administers direct federal student loan programs for higher ed, which would go away if the department were abolished outright. HUD's abolition would mean no more Section 8 housing vouchers, Federal Housing Administration–backed loans, and no more Hope VI rehabilitations of housing projects.

It's of course possible to abolish these departments and move these programs around. But the scale of Paul's cuts, and other legislation he introduced, clearly indicate this isn't what he means. Cuts of $78 billion and $53.1 billion reflect outright repeal of programs, not rearrangement. Paul also introduced the Cut Federal Spending Act of 2011, which explicitly states that "all Department of Education programs are defunded effective on the date of enactment of this Act, except for the Pell grant program which shall be capped at $16,256,000,000," and "all accounts and programs of the Department of Housing and Urban Development are defunded effective on the date of enactment of this Act" (save veterans' housing programs). It's clear that Paul didn't want to merely rearrange these departments' functions: he wanted to get rid of them altogether.

Moreover, in all three budgets Paul argues against federal involvement in education or housing, blaming the former for worsening school performance and the latter for the housing crisis.

4) Either eliminating or drastically cutting two of the biggest programs for the working poor

The proposal: Paul would either eliminate or render nonrefundable the Earned Income Tax Credit and the Child Tax Credit; the former is the US's most significant cash transfer program for non-elderly poor, and the latter also provides substantial assistance to low-income people.

Which budget(s): FY2012 for making nonrefundable, FY2013 for eliminating.

Details: Paul's first budget is the clearest on this point, and includes a specific proposal to "prevent payments when earned income credit and child tax credit exceeds tax liability." That almost entirely eliminates the EITC. Last year, the Joint Committee on Taxation projected that the credit as a whole would cost $70.4 billion in 2015, and $61.8 billion of that (87.8 percent) comes from the refundable portion. The CTC would also be cut by more than half. The credit as a whole is projected to cost $57.3 billion this year, and $33.7 billion of that (58.8 percent) is from the refundable portion.

The FY2013 budget also states that payment when EITC or CTC exceeds tax liability is eliminated. But it goes a bit further than that. The section of the budget detailing Paul's flat tax plan includes this sample tax return form:

Conspicuously absent are any non-mortgage interest credits or deductions — including the EITC and CTC.

5) Eliminating or slashing all foreign aid, including to Israel

The proposal: Paul would eliminate US funding for international assistance programs, including military assistance to allies like Egypt and Israel, or else reduce it to $5 billion, far below the roughly $37 billion the US spends annually at the moment.

Which budget(s): FY2012 for eliminating all aid, FY2013/2014 for reducing to $5 billion.

Details: For the most part, Paul's budgets have taken a consistent line on foreign aid, insisting that it's ineffective if not counterproductive for recipient countries (a disputed view, to say the least) and that it coddles dictators, and implying that it's inappropriate to use US funds to help other countries. (The section of the FY2014 budget devoted to foreign aid is titled "Putting America First: A New Direction for Foreign Assistance.")

The FY2012 budget explicitly acknowledges that it would eliminate foreign assistance for Israel. Paul defends this as helpful to Israel's economy in the long run, quoting economist Alvin Rabushka: "Free money is the scourge of Israel’s economy. It is the difference between a free, prosperous Israel and a statist, dependent Israel." Paul makes clear that he does not want to single out Israel; he merely wants to eliminate aid to it the way he wants to eliminate all aid.

The FY2013 and FY2014 budgets change his proposal to merely cutting aid dramatically, rather than eliminating it outright. They do not mention Israel, but they, like the FY2012 budget, cite Egypt as an example of a dictatorial regime receiving aid, implying that it's an inappropriate recipient. The US has traditionally provided military assistance to both Egypt and Israel as a way of enforcing the Camp David Accords; it could not eliminate that aid without risking an end to that agreement.

6) Big defense cuts

The proposal: Paul's budgets call for defense cuts, though his office has tried to minimize the scale of the cuts since then.

Which budget(s): FY2012 and FY2013, arguably FY2014.

Details: Paul's views on defense spending have evolved considerably. His initial FY2012 budget would have reduced spending in FY2016 by about 30 percent, relative to CBO projections. His FY2013 budget included a cut of a similar scale. Both budgets explicitly defended this drawdown. "Military funding has often far outpaced not only our most likely enemies, but has often outpaced the entire world’s military spending combined," both budgets state. The FY2012 budget calls for a "draw-down and restructuring of the Department of Defense."

The FY2014 budget includes the same pro-drawdown rhetoric as the first two. All three budgets include a quote from President Eisenhower: "We will bankrupt ourselves in the vain search of absolute security." The FY2014 budget, in its own words, "does not simply reduce military spending, but provides directives to realign the military for the 21st Century"; it "seeks to reduce the size and scope of the military complex, including its global footprint to one that is more in line with a policy of containment."

But Paul's office insisted to PolitiFact's Steve Contorno that once you take into account the fact that FY2014 assumes a total end to US war spending, it actually increases defense spending. It's worth noting here that while the FY2012 and FY2013 budgets were judged against a baseline where the sequestration didn't take effect, by the time the FY2014 budget was released the sequestration was clearly coming, and increasing spending relative to deep defense cuts that no one in either party supports is not that ambitious.

Correction: An earlier version of this post suggested that eliminating the Department of Housing and Urban Development would eliminate federal oversight over Fannie Mae and Freddie Mac. That's incorrect: they're supervised by the Federal Housing Finance Agency, an independent agency separate from HUD.

Update: This post has been updated to reflect the comments of Paul spokesperson Jillian Lane.

WATCH: 'Third parties, the underpants gnomes of politics'