The Times also tells us that the legislation “calls for the most sweeping welfare changes since the New Deal.” That one’s true. And because it’s true, welfare reform presents Clinton with perhaps the toughest domestic decision of his presidency. He can sign the bill and deliver on his slippery New Democrat pledge to “end welfare as we know it.” He can veto the bill and please his party’s left wing. But he cannot indulge his natural tendency to do both.

What most call “welfare” is Aid to Families with Dependent Children. It has always been unpopular because, alone among New Deal institutions, it sends cash to able-bodied people–mainly single mothers and their children–who could be working. In FDR’s time there were only a few hundred thousand families on the rolls, most headed by widows. Today, AFDC supports more than 4 million single mothers, half never married. Both Newt Gingrich and Clinton blame AFDC for sustaining what the president has called a “culture of poverty”–an “underclass” of single-parent, nonworking households.

The pending reform would abolish AFDC, replacing it with fixed-sum “block grants” for states to spend on aid programs of their own devising. That would let states radically change the rules of the welfare game. They wouldn’t have to limit benefits to five years, but they wouldn’t have to pay benefits for five years, either. They could impose a two-year limit, or, if they wanted, a two-day limit. It all amounts to an unprecedented shift of power out of Washington. A state might even end cash aid entirely.

These possibilities are what terrify liberals. Democratic Sen. Daniel Patrick Moynihan calls the bill an “obscene act of social regression.” The prediction is that states will “race to the bottom,” slashing benefits to encourage the poor to move elsewhere.

But welfare block grants also have a powerful, often overlooked rationale. Moynihan likes to quote UCLA social scientist James Q. Wilson, who argues that when it comes to addressing the underclass problem, “I do not know what ought to be done and assert that I do not think anyone else knows, either.” What Moynihan doesn’t quote is Wilson’s conclusion, which is that the way to find out what works is through the explosion of state welfare experiments block grants would provoke. Some states will try replacing welfare with public-service jobs, as Wisconsin wants to do. Some will try more of the training schemes authorized in Moynihan’s mild 1988 reform. Some will try harsh “cold turkey” cutoffs. Will getting tough really encourage single women to marry before having children? How many aid recipients simply can’t handle working? We will find out.

If Clinton signs the bill, that is. The Republicans dropped the biggest “poison pill” to which the president objected: the block-granting of Medicaid. But–cynically encouraged by the Dole campaign, which would like to run against a Clinton welfare veto–Congress has kept a few unpleasant mini-pills, including cuts in food stamps and a ban on many benefits to legal immigrants.

Liberals hope Clinton will be persuaded to veto the bill by a last-minute Urban Institute study predicting the legislation will cause a 12 percent increase in child poverty. Yet, as White House spokesman Mike McCurry has pointed out, poverty statistics measure only how much money children’s families have–not if they have fathers at home, or whether they’re growing up in neighborhoods of drug dealers or of working parents. If welfare reform can turn recipients into workers (as the Urban Institute also predicts will happen), the children now trapped in the culture of poverty will ultimately be better off.

For all its risks, the bill being sent to Clinton probably represents the nation’s best hope for figuring out how to solve its underclass problem. But Clinton will have to brave furious criticism from activists and editorialists clamoring for a veto and invoking his own rhetoric about “protecting the children.” Can a president who famously wants to be loved stand it? We will find out.

Congress wants to undo 60 years of assistance to the poor. Key points:

Give new authority to states by replacing a federal guarantee of individual welfare payments with annual block grants to the states

Almost half the 6-year, $60 billion savings comes from cuts in food stamps

Bar legal immigrants who have not become citizens from many benefits