After months of circling warily around the multibillion-dollar savings and loan scandal, Republicans and Democrats last week began to answer a question that has been on the lips of taxpayers for some time: Who's to blame?

Each, of course, has found the other responsible.

The White House has taken the initiative so far, accusing Democrats of having played "a big role" in what has become the nation's largest fiscal scandal.

Republicans point to what they call a "sleaze factor" among Democratic congressmen, many of whom, though no longer in office, had close ties to the lobbying machinery of the thrift industry over the last decade, especially the U.S. League of Savings Institutions.

And they single out efforts by a Democrat-controlled Congress to forestall White House efforts in 1987 to enact a bailout package of $15 billion, which, although hardly enough to put a dent in the crisis, was better than nothing.

But Democrats believe they have some powerful ammunition of their own. The most potent is this: The Republicans controlled the White House during the roaring 1980s, when the fiasco unfolded, and the president bears primary responsibility for regulating and weeding out fraud in the thrift industry.

The Reagan and Bush administrations, Democrats argue, have been the cops on the beat, but for years were too blinded by deregulatory zealotry to do their job. And as far as congressional culpability goes, they argue, the Republicans controlled the Senate during much of the decade, from 1981 through 1986.

As the cost of the savings and loan cleanup mounts -- it already is expected to surpass $180 billion -- the debate is likely to get even more heated and focus on a number of key points:

The Bush role. George Bush, as vice president during the Reagan White House, headed the administration's task force on deregulation and supervision of the banking industry. In that position, he would have been expected to have worked closely with the nation's banking regulators and to have studied the thrift problem along with top aides. Yet he failed to bring the subject to the public's attention, either as vice president or during his presidential campaign in 1988, when he promised no new taxes.

But the issue had a life before this.

The $100,000 guarantee. Congress decided in 1980 to raise the deposit insurance ceiling to $100,000 per account, up from $40,000.

The California thrifts, the largest in the industry, were the main advocates for the increase, which they thought would help lure large deposits through their doors. The U.S. League of Savings Institutions, the largest thrift lobby, pushed hard for it. Runaway inflation in the late 1970s convinced members from Republican and Democratic ranks in the House and Senate that some increase was warranted.

In the spring of 1980, as House and Senate members were working out a compromise on banking legislation, the conference committee was temporarily adjourned so that several key congressmen could retreat to a back office. There, according to several of the men in the room or their spokesmen, despite a lack of public discussion on the issue, then-Sen. William Proxmire, (D-Wis.), Sen. Alan Cranston (D-Calif.), Sen. Jake Garn (R-Utah) and then-Rep. Fernand J. St Germain (D-R.I.) decided to raise deposit insurance to $100,000. They telephoned banking regulators to inform them of the decision.

"I begged, literally begged, Senators Bill Proxmire and Jake Garn to hold the figure down to $75,000, which would have kept it in line with inflation," recalls Irvine Sprague, then chairman of the fund insuring bank deposits. But it was to no avail.

The result was what economists call the moral hazard: Neither depositors nor bankers were left with any incentive to carefully watch how large thrift deposits were invested because the federal government guaranteed consumers against loss.

The decision was the first step in ushering in a new breed of depositor: Money brokers from Wall Street, who for a fee pulled and placed $100,000 chunks of money around the country wherever a thrift was offering the highest rate. Because failing thrifts desperate for cash tended to offer the highest rates, this helped keep alive the biggest money losers.

The Reagan White House. When Ronald Reagan took over the White House in 1981, his transition team members circulated a memo among themselves about the thrift industry's problems that warned, "the new administration may well face a financial crisis not of its own making ... Confidence in the entire financial system could evaporate."

The chairman of the Federal Reserve Board, Paul Volcker, had decided in 1979 to wring inflation from the economy by raising interest rates. When interest rates skyrocketed into the double digits the next year, thrifts found themselves squeezed. They had to pay double-digit interest rates to lure depositors. But they were only earning single-digit rates on old home loans.

This so-called interest-rate squeeze -- where thrifts were paying more for money than they were earning on it -- plagued the industry.

The White House, which ran its business through committees called Cabinet Councils, formed a thrift working group headed by then-Treasury Secretary Donald Regan to watch over the thrift problem and recommend solutions. In the group was White House aide Ed Gray.

The group decided in 1981 that closing the hundreds of insolvent thrifts that existed across the county -- possibly as much as 95 percent of the industry -- would cost $100 billion and was unnecessary. Once interest rates came down, some thrifts would be restored to health. So they decided, with White House approval, to wait and devise ways to enable insolvent thrifts to escape the clutches of bank regulations that required insolvent institutions to be closed.

The White House, in conjunction with Treasury and thrift regulators, loosened accounting rules so ailing thrifts could look healthy. And they issued government notes that made troubled thrifts appear solvent. They decided the notes would not count as part of the budget deficit; as a consequence, government obligations of billions of dollars were being racked up without the public's knowledge.

They also deregulated the thrifts, allowing them into new areas of business in hopes that this would help avoid future interest-rate traps.

Interest rates did come down, but the thrifts by this point were besieged by another problem: bad loans stemming from their ventures out of home mortgages and into risker areas such as commercial real estate and options markets. They had been urged into those ventures by the Reagan White House and its appointed thrift regulator, Richard Pratt, who loosened the reins and prodded the industry to diversify out of home mortgages to avoid being tossed and turned by "the interest-rate squeeze."

The states and regulators. In the early 1980s, states like California, Texas and Florida loosened regulations governing what state-chartered but federally insured thrifts within their borders could do.

In California, the Republicans led the deregulation effort. In Texas, the Democrats did.

The federal government also deregulated the rules governing federally chartered thrifts. Thrift regulator Pratt lifted many restrictions. For example, he allowed thrifts to make loans to home buyers who put no money down, to invest in futures and options markets and to buy junk bonds.

Congress, through a 1982 bill sponsored by Garn and St Germain, further loosened federal restrictions, although not as widely as states had.

Neither the states nor Congress beefed up supervision to make sure institutions didn't abuse their new-found freedom. In 1984 and 1985 the White House and Congress ignored the pleas of Reagan-appointed thrift regulator Gray, who replaced Pratt, for more supervisors. They also ignored Gray's pleas to curb brokered deposits and to curb the ability of thrifts to invest directly, rather than indirectly through loans, in commercial real estate.

The thrift crises in Ohio and then Maryland in 1985 further alerted regulators to the crisis brewing nationwide. But the White House elected to remain quiet and pursue a policy of allowing failing thrifts to try to diversify and grow out of their problems.

The $15 billion decision. In 1986 and 1987, then-Treasury Secretary James A. Baker III proposed a $15 billion bailout plan that administration officials knew was too little but had decided was better than nothing. They knew the actual cost of the cleanup was closer to $50 billion, but didn't say so, former Treasury officials now acknowledge. They argue it would have been irresponsible to frighten the public by describing the size of the problem at a time when they say they believed Congress was unlikely to provide any more than $15 billion to solve the S&L crisis.

But critics respond that Congress could not act responsibly without full information on the scope of the problem.

The Republican and Democratic lobbyists from the U.S. League of Savings Institutions, as well as Democrats Jim Wright, then speaker of the House, and St Germain, then chairman of the House Banking Committee, worked to sabotage quick passage of the Baker plan, according to a House investigation of the process.

The proposed legislation eventually was reduced to $10 billion and its passage was delayed for 18 months, until August 1987, adding billions of dollars to the cost of the final bailout in the meantime.

The 1988 election and after. In 1987 through the fall election of 1988, the White House and Gray's successor, M. Danny Wall, vastly underestimated the size of the thrift problem. Bush did not mention it during the campaign. But even as he criticized Harvard University as a bastion of liberalism, Bush hired two Harvard professors in the summer of 1988 to devise a bailout plan he could unveil after he was sworn in.

Bush campaign officials ranked the thrift crisis among the top issues they would have to handle during the election and once in office. By late 1988, it was clear to many in the Reagan-Bush administration that taxpayer funds would have to be used to clean up the thrift mess.

Publicly, thrift regulator Wall, who had been a banking aide to Garn for years before Garn promoted Wall's nomination to become chief thrift regulator, denied tax dollars would have to be used and vastly underestimated the cost of the cleanup.

The White House said nothing one way or another.

In the fall of 1988, even though the fund that insured deposits at thrifts was insolvent, Wall committed billions of dollars in federal aid to entice billionaires like Robert Bass, Ronald Perelman and Caroline Hunt to assume ownership of failed thrifts.

The money for the aid eventually had to be raised through taxpayer dollars amounting to at least $52 billion. Neither the Treasury nor the White House asked Wall to halt the sales.

The cleanup package. President Bush unveiled a rescue and reform package in February 1989, but it encountered opposition in Congress, mostly from Republicans, who sided with the thrift industry's attempts to preserve the looser regulations that it had won during the Reagan years.

Democrats such as Sen. Howard Metzenbaum (D-Ohio) and Rep. Henry B. Gonzalez (D-Tex.), along with a minority of the GOP in Congress, including Rep. Jim Leach (R-Iowa), toughened the legislation and helped push it through.