When the House Ways and Means Committee finished work on President Carter's tax-cut bill last week, Thomas J. Reese, lobbyist for Taxation With Representation, wryly assessed how liberals "tax-reform" efforts had fared.

"The worst thing that happened to tax reform," Reese proclaimed with deadpan solemnity, "was when Fanne Foxe fell into the tidal basin." After that, he quipped, "it all went downhill."

Reese' tongue-in-cheek reference was to the congressman-and-the-stripper incident in 1974 that ultimately led to the toppling of the once-powerful former Ways and Means chairman, Rep. Wilbur D. Mills (D-Ark.).

It had long been the contention of liberals in the 1960s that one of the major obstacles to achieving real "tax reform" was the presence of Mills, a consensus-seeking conservative who had no enthusiasm for sweeping change.

"If we only could get rid of Wilbur," the liberals would say, "then we'd really be able to push through tax reform."

But unseating Mills wasn't the only thing the "tax-reform" advocates dreamed about back in those days. Another perceived roadblock to tax reform was the makup of the Ways and Means Committee.

The panel consisted mostly of Republicans and Southern conservatives, the bulk of whom were opposed to tax-reform in principle. There was a handful of liberals, but there were too few to wield any power.

"If we only could get a few more liberals on the panel," the reformers said, "then we'd really be in a position to push through tax reform."

There also was the Ways and Means Committee's penchant for secrecy and backroom dealing. Most of the panel's sessions then were closed to the public. The big deals were struck behind the scenes, with only the lobbyists present.

The liberals were sure this was another big barrier to reform. "If only we could open up the committee's meetings," they said, "surely we'd have a wedge toward pushing through tax reform."

Finally, there was the absence of any leadership from the White House. To be sure, Lyndon Johnson's Treasury produced a paper supporting tax reform - but only at the eleventh hour, barely days before leaving office.

The Nixon and Ford administrations made some "reform" proposals, but too often these involved some sort of breaks for big business. The liberals yearned for a populist Democratic president who would truly fight for reform.

"If only we had a president who was willing to take the lead," they told each other. "Then we'd really have a good chance at pushing through tax reform."

Of course, during those bleak years, Congress did take some steps toward "tax reform": In 1969, with Mills and Nixon both in power, the lawmakers passed a sweeping tax reform bill, which some now criticize as excessive.

And in 1976, the House and Senate enacted another major "tax reform" bill, which today conservatives are trying to roll back. Instead, by 1978 standards, the 1976 bill seems almost radical.

Well, to get back to the story, in the meantime, the liberals got their wishes - or, at least, it seems, the unimportant ones:

The 1974 tidal basin incident with Fanne Foxe - which laid bare a tryst between Mills and his stripper friend - effectively plunged Mills's career into the drink as well.

The Arkansan bowed out as chairman in 1974. In his place came Rep. Al Ullman (D-Ore.), a smiling, mainstream Democratic liberal who was less autocratic than Mills and more sympathetic to "tax reform."

Later, the new Democratic congressional leadership, under Rep. Thomas P. O'Neill (D-Mass.), as House speaker, assigned more liberals to the Ways and Means Committee. In fact, the panel was almost doubled to accommondate them.

The new House "sunshine" laws forced the committee to begin holding open hearings. And Ullman decreed finally that staffers make public in advance which special interest groups would benefit from every tax break proposal.

Finally, in 1976, the liberals got a political bonus: The nation elected a President who not only favored massive tax reform, but promised to back it. To Jimmy Carter, the existing tax code was "a disgrace to the human race."

Well, with all those wishes finally come true, pushing through major tax reform legislation should have been a piece of cake, eh? All the old barriers were knocked for a loop.

Not if you look at the Ways and Means Committee's new tax bill:

Not only is there no "tax reform" in the new legislation - Carter's proposals were all rejected - but the Ways and Means bill actually would reverse some of the major tightening in capital gains laws enacted in 1969 and 1976.

For the first time in recent history, the committee skewed the tax reductions in the bill more toward the better-off taxpayers in the $20,000 to $50,000-a-year brackets, rather than those in the $15,000 and below levels.

And, to top it all off, both the Ways and Means panel and the Senate Finance Committee seem bent on repealing many of the other "reforms" in the 1969 and 1976 legislation - such as cracking down on taxing Americans overseas.

"By comparison, the 1969 and 1976 laws look like landmark legislation," one tax reform lobbyist mused last week. "We got more with Mills, without the extra liberals, with secrecy, and with Nixon and Ford, than we got this year."

Why?

Well, for one thing, the changes didn't all work out that well. Ullman isn't as strong a leader as Mills; the liberals on the panel are in disarray; the open meetings have heightened the dealmaking; and Carter bungled the bill.

But the major reason is that the liberals learned to their dismay that despite their own earnest wishing, the electorate didn't fully share their views about "reforming" the tax system.

In a word, voters want their own taxes reduced, but they don't want to soak the rich. If anything, it seems, they want more tax "loopholes" in the code - to take advantage of themselves.

Of course, that shouldn't kill off all the reformers' hopes for the future.

From the liberals' point of view, there's always the possibility that Carter won't be re-elected, that Congress will return to close meetings, that conservatives will regain their seats and that Mills will make a comeback.

"If only we can get those four things accomplished," one liberal said wishfully last week, "then we really will be able to push through tax reform."