Washington (CNN) - House Budget Chairman Paul Ryan, R-Wisconsin, will unveil a highly anticipated 2012 Republican budget proposal Tuesday that would cut about $6 trillion over 10 years, according to GOP sources familiar with the document.
The plan, the most detailed economic guidepost for the new House GOP majority, would also mean dramatic changes to those political lightning rods - entitlements.
The GOP budget blueprint calls for a controversial overhaul of Medicare, the health care program for seniors. And it imposes deep cuts in Medicaid, which provides health benefits to low-income Americans.
The current Medicare program would be dismantled, starting in 2022. The government would no longer directly pay bills for seniors in the program. Instead, recipients would choose a plan from a list of private providers, which would be subsidized by the federal government.
In an op-ed in The Wall Street Journal, Ryan says that reform "will guarantee that Medicare can fulfill the promise of health security for America's seniors."
Ryan often calls Medicare a major driver of America's debt, and another central goal of his proposed changes to the program is to help reduce the debt and deficit.
GOP sources familiar with the plan stress anyone 55 or older now would not be affected by the changes.
On Medicaid, Ryan's plan calls for deep cuts and another fundamental change: The federal share of the Medicaid system would become block grants to the states.
CNN is told that the House GOP budget plan does not call for significant change to the Social Security program. Republicans argue that while Social Security is a factor in the nation's fiscal crisis, it doesn't contribute as much to the soaring debt as Medicare.
Two House GOP lawmakers briefed on the proposal told CNN that they and others on the House Budget Committee believe it's a mistake not to tackle Social Security.
As for so-called discretionary spending, Ryan says he would bring down spending on domestic government agencies to below 2008 levels.
GOP sources have told CNN his plan is to cut spending back to 2006 levels. It's unclear how much that would slash, but it would be more than the $61 billion in spending cuts House Republicans approved earlier this year.
Ryan says his savings proposals are "numerous and include reforming agricultural subsidies, shrinking the federal work force through a sensible attrition policy, and accepting Defense Secretary Robert Gates' plan to target inefficiencies at the Pentagon."
The budget would also cut the corporate tax rate from 35% to 25%, but at the same time do away with tax loopholes for corporations. Those loopholes helped General Electric find a way to pay no taxes last year, sparking outrage. Ryan says his proposal would help prevent that.
"It maintains a revenue-neutral approach by clearing out a burdensome tangle of deductions and loopholes that distort economic activity and leave some corporations paying no income taxes at all," said Ryan in his op-ed.
Ryan's plan also provides for a permanent extension of all the Bush-era tax cuts. Under a compromise with President Barack Obama, were extended last year through 2012.
A GOP source said even with the major cuts and changes in Ryan's proposal - essentially a blueprint that guides spending decisions and does not go to the president for his signature - it would not bring the budget into balance for many years.
House Republican leaders have been signaling for some time that they plan dramatic and controversial changes to entitlement programs bring down the budget deficit and debt. Ryan said Sunday he knows his budget is giving Democrats a "political weapon" against Republicans.
Already Democrats have been issuing statements attacking the plan.
"It is now clear that the Republican budget is not bold, but the same old ideological agenda that extends tax breaks to millionaires and big oil companies while cutting our kids education and health security for seniors," said Rep. Chris Van Hollen, the top Democrat on the House Budget Committee.
A spokesman for the House Democrats' campaign arm told CNN that Democrats are already planning to target up to 50 House Republicans, challenging them for supporting Ryan's plan, which they were arguing would "dismantle Medicare for seniors" even before details on the plan were unveiled.
One news release focused on freshman Texas Republican Blake Farenthold, who narrowly won election last fall.
"House Republican leaders are now full-speed ahead on a partisan plan that would dismantle Medicare for seniors," said Jesse Ferguson of the Democratic Congressional Campaign Committee. "Now is the chance for Rep. Blake Farenthold to stand up and say he won't end Medicare as we know it because it's too important to seniors. If Rep. Blake Farenthold can't stand up for Texas seniors now against ending Medicare, then he never will."
Knowing that the proposed changes will be politically risky and elicit an onslaught of criticism, Ryan and Republican Whip Kevin McCarthy of California have been holding sessions two or three times a week with House Republicans to try to arm them with facts and figures about the gravity of the debt problem and why it needs to be fixed.
CNN was allowed into one of these meetings last month and heard Ryan lay out in stark terms what he calls the "tidal wave" of debt the country is facing.
"The Congressional Budget Office has this economic model where they measure the economy going forward, and they are telling us that the entire economy crashes in the year 2037 because their computer simulation can't conceive of any way in which the U.S. economy can continue," Ryan told the GOP group. "By the time my kids are my age, just those three programs - Social Security, Medicaid and Medicare - will consume all federal revenues. There will be no room for anything else in the federal budget."
When Ryan proposed a version of his Medicare overhaul idea last year, known as his "road map," Democrats skewered it and tried to use it as a campaign weapon against Republicans across the country.
Obama has often said it is important for Washington to address entitlement spending. But the president has not offered any specific proposals, and Republicans suggest he is unwilling to back this rhetorical call with specifics because he wants the GOP to take the first risky steps.
Multiple GOP sources admit the timing of Ryan's 2012 budget proposal is tricky. It is being released in the middle of down-to-the-wire, contentious negotiations with Democrats about a spending measure to keep the government running for the rest of this 2011 fiscal year.
CNN is told GOP leaders considered delaying the release of Ryan's budget until this year's spending differences are resolved.
However, they decided to go ahead with it because they hope showing major cuts and reforms planned for next year will help calm rank-and-file conservatives who are unhappy their leadership is compromising too much on spending cuts now.