So far, our nation’s budget debate has been a desultory affair focused on whether a small slice of the federal government’s outlays should be cut by $33 billion or $61 billion, or whatever.

But Americans are about to learn how much is at stake in our larger budget fight, how radical the new conservatives in Washington are, and the extent to which some politicians would transfer even more resources from the have-nots and have-a-littles to the have-a-lots.

And you wonder: Will President Obama welcome the responsibility of engaging the country in this big argument, or will he shrink from it? Will his political advisers remain robotically obsessed with poll results about the 2012 election, or will they embrace Obama’s historic obligation — and opportunity — to win the most important struggle over the role of government since the New Deal?

This week, Rep. Paul Ryan (R-Wis.) will announce the House Republicans’ budget plan, which is expected to include cuts in many programs for the neediest Americans.

The Ryan budget’s central purpose will not be deficit reduction but the gradual dismantling of key parts of government. Remember that Ryan wants both to preserve the Bush tax cuts and, over the long run, to enact more breaks for the wealthy, including the elimination of the capital gains tax.

Ryan’s plan reportedly will include steep Medicaid cuts, disguised as a proposal to turn the program into a “block grant” to the states. The net effect would be to leave even more Americans to the mercies of the private insurance market.

In deference to the GOP’s success in turning last year’s health-care law into “Obamacare,” let’s call this proposal Ryancare — and let’s make sure we look carefully at its impact on the elderly and the disabled, the main beneficiaries of Medicaid.

Put the two parts of the Ryan design together — tax cuts for the rich, program cuts for the poor — and its radically redistributionist purposes become clear. Timid Democrats would never dare embark on class warfare on this scale the other way around.

But while I am assailing his ideas, let me put in a good word about Ryan himself: He is, from my limited experience, a charming man who truly believes what he believes. I salute him for laying out the actual conservative agenda. Here’s hoping he is transparent in the coming weeks about whom he is taking benefits from and toward whom he wants to be more generous. If he thinks we need an even more unequal society to prosper in the future, may he have the courage to say so.

The other clue as to where conservatives are going was the Senate Republicans’ so-called balanced budget amendment, announced Thursday. I usually resist the term “so-called,” but it’s appropriate here because this amendment is not about balancing the budget. It is about eviscerating government.

And it’s not even honest on its own terms. It says federal outlays should not exceed 18 percent of gross domestic product without a two-thirds vote in Congress. But the words in the amendment say this number would be calculated on the basis of “the calendar year ending before the beginning of such fiscal year” — my emphasis — meaning it delays taking into account economic growth.

The result, according to an analysis by the Center on Budget and Policy Priorities, would be to limit federal spending to about 16.7 percent of GDP.

And when was the last time federal spending was that low? In 1956, the center reports, when “Medicare and Medicaid did not exist and millions of workers . . . were excluded from Social Security.” Oh yes, and we didn’t have much federal aid to education then, or most of our environmental protection initiatives, or “basic programs to ease poverty and hardship such as Supplemental Security Income for the elderly and disabled poor, food stamps, and the Earned Income Tax Credit.”

One other thing: The amendment would require a two-thirds majority to raise taxes, giving a right-wing minority veto power over any tax increases. Goodbye, majority rule.

This is all extreme and irresponsible stuff. The president knows it. The coming week will test who he is. When Ryan releases his budget, will the president finally engage?

“This is our time,” Obama liked to say during the 2008 campaign. This most certainly is his time to stand up for the vision of a practical, progressive government that he once advanced so eloquently.

ejdionne@washpost.com