Who was an original supporter of the proposal for a sharp rise in D.C. estate taxes, approved by the City Council on a 12-to- 1 vote two weeks ago and then unanimously rejected Tuesday in the face of intense public pressure?

In the highly charged political atmosphere of a council on which many members are running for some other office and no one wants to be on the wrong side of a controversial issue, finding original supporters is almost, as difficult as finding someone who admits to reading the measure closely before the first vote was taken.

"It was stupid of us, no question about it, not to have focused on what it would have meant," said council member Polly Shackleton (D-Ward 3), who offered the motion to reconsider the estate tax bill. "I can't say it was a really responsible thing to do."

The story of the council's action on the estate tax is an anatomy of how the legislative process in the city works, how bills sometimes are passed -- or almost passed -- into law with minimal scrutiny.It also illustrates how the D.C. City Council, despite the grass-roots activist background of many of its members, sometimes responds in almost knee-jerk fashion to the complaints of those considered the backbone of American voters -- middle- and upper-income taxpayers.

The bill would have raised taxes on the estates of persons who die in the District -- already substantially higher than those in Maryland or Virginia -- by an average of 40 percent. The additional tax would have fallen more heavily on upper-income residents, although middle-class homeowners would have been affected as well.

Council member John A. Wilson (D-Ward 2), who introduced the bill as a minor revision of an earlier measure proposed by Mayor Marion Barry, was the bill's lone strong supporter Tuesday. But in the end, not even Wilson voted to let stand a tax increase that sneaked up on the people who approved it.

The first proposal to change the city's inheritance tax system came two years ago in a bill put forth by Barry.

Wilson scheduled a public hearing for May 31, 1979. The council is not required to hold hearings for most of its legislation, but generally does on items of widespread interest -- such as taxes.

But no one signed up to testify at the hearing, so Wilson canceled it.

The Barry bill died at the end of last year's council session. Meanwhile, Wilson and the clerk of his Committee on Finance and Revenue, Jacqueline Helm, began to tinker with Barry's bill to respond to written concerns expressed by a few groups, including the D.C. Bar.

Working with Barry's Finance and Revenue Department and the mayor's Office of Intergovernmental Relations, Wilson and his staff came up with a bill that he introduced earlier this year.

Wilson's version would have done three major things, only two of which the members of his committee focused on in an April 28 meeting on the bill:

It would have changed the D.C. tax from an inheritance tax against the individual amounts received by various heirs to a tax on the entire estate before it is apportioned.

It would have brought the District's estate-taxing system into closer conformity with the federal system.

It would have imposed the overall 40 percent increase in death taxes. The latter effect went by unnoticed, council members now say.

Helm had produced a committee report that explained the impact of the bill, which states clearly at one point that the tax "would increase District revenue from death taxes by approximately 40 percent."

But some council members acknowledged this week that they did not find time to read either the bill or the report, and others who said they did read it said they voted for the tax to go along with Wilson's wishes as chairman of the committee.

"I don't know that I read it, and frankly I don't recall any discussion about comparisons with Maryland and Virginia," said Shackelton, a member of the committee. But an attachment to the report provided a chart that demonstrated the wide gap between the District and suburban jurisdictions under the new tax.

The only council member who voted against the measure in committee was Betty Ann Kane (D-At Large), who said she had stayed up late the night before going over the bill with her husband, Noel, an attorney, and developed reservations.

Kane said she was concerned about the new bill's heavier impact on insurance policies, and the fact that it fell heavily on surviving children in some circumstances.

David A. Clarke (D-Ward 1), another committee member, said he asked questions about the tax at the April 28 meeting and had reservations, and later even tried to draw up amendments to lower the tax rates.

But he was not recorded as voting against the measure then, nor on the other two occasions when the tax received new-unanimous council approval.

The bill was a complicated one, and council members often defer to Wilson, the chairman of the finance committee, on tax measures. One council staff member said she just assumed that whatever problems that existed in the legislation had been worked out beforehand by the staff of Wilson's committee. l

The committee system is a fact of life at the District Building as in most other legislative headquarters, with little legislation making it out of committee without the chairman's blessings.

"I'm a junior member," said freshman council member H. R. Crawford (D-Ward 7), who also voted to approve the tax in committee. "I was told that this had been around for a long time. I was told that the chairman (Wilson) wanted it. I have a lot of legislation before his committee. The chairman has quite a bit of power."

Once out of committee, the seemingly innocuous estate tax bill went to the full council, where it was placed on the consent calendar -- a grouping of noncontroversial items all approved with a single vote.

At first reading of the legislation, Kane had the item taken off the consent calendar so that she could argue against it and have her no vote recorded. She did the same thing at the council's meeting two weeks ago, when the measure came up for final approval.

But the rest of the council went along with Wilson, who still maintains that the measures was a good tax. "We have an unwritten rule -- pretty much rely on the chairperson of the committee," said Nadine P. Winter (D-Ward 6). "We are politicians, not technicians. We miss a lot of technical points on a bill."

Winter said she had questions about the bill, but said she did'nt want to be isolated against it. "One person, standing alone, you'll get the reputation that you're always obstructing," she said. "That was [former council member] Doug Moore's style."

There had still been no hue and cry from District residents. Then on June 11, a newspaper story detailed the effects of the already-approved tax, which by then was awaiting Barry's signature. The phone calls started coming in.

"The first call I got was from a friend of mine who's an attorney," said John Ray (D-At Large). "He said, 'John, how could you vote for such a thing? Did you read it?' And I had to admit that no, I probably didn't."

The telephone calls came in for much of the day, with many of the calls coming from affluent Ward 3 residents but some also coming from homeowners in other parts of the city who, mainly because of their real estate, found themselves with six-figure estates that would be heavily taxed under the bill.

"I was getting . . . phone calls from Ward 7," said Crawford."Homes there that people bought for $15,000 are now worth $75,000. This bill would have affected the rich far more than the average taxpayer, but it also had negative effects for the average middle-income Washingtonian."

Wilhelmina J. Rolark (D-Ward 8), who represents the city's poorest ward, said she understood that the bill was designed to fall more heavily on the rich and said she received only a handful of protest calls from constituents. But she said she voted for the reconsideration because she did not want to be considered disruptive.

On Monday, Shackleton circulated a memo saying she wanted a vote to reconsider. Chairman Arrington Dixon called Wilson, as did several other council members. The vote to reconsider was unanimous, and Wilson now says he will shelve the bill.

"It says something about the caliber of people on this council," said Wilson. "I don't think everybody read it. I was surprised it moved as smoothly as it did.

"I take the responsibility. I didn't do anything under the table. I didn't do anything what wasn't aboveboard."