It was 1976, that year of all the talk about reforming the federal government up in Washington, and Ed Jenkins and Jim Guy Tucker were right there on the front row.

Jenkins got elected to Congress from a district in Georgia. Tucker was sent to the House from the 2nd District of Arkansas.

Both of them young men, both of them attorneys, both of them Democrats and, as the luck of the draw had it, both were assigned to the Ways and Means Committee.

Now, the Ways and Means Committee, where the tax laws are written and finagled with, is not exactly a garden spot of progressive thinking, but it quickly became a focal point for the reformers.

At the head of the pack was Jimmy Carter, the newly elected president, promising to shake up Washington and reform the U.S. tax code, which he called a disgrace to the human race.

Clearly, then, if disgraces to the race were to be dealt with, Ways and Means was a good assignment for an eager new congressman. Ed Jenkins and Jim Guy Tucker were pleased as punch with their luck.

So when Jimmy Carter's tax revision proposals finally made their way to Capitol Hill early this year, after months of debate within the administration, the two new congressmen were poised and ready for the fray.

But the fray they expected, a riproaring battle between reformers and special interests, never happened. Therein lies a story.

One of Carter's proposals would phase out a section of the tax law that exempts U.S. companies from paying a portion of the tax on products they export - a section known as "DISC," for Domestic International Sales Corporations.

According to the Treasury, in 1976 the DISC section allowed companies to keep $1.1 billion that otherwise might have gone to the government in the form of income taxes.

The idea behind the DISC, created in 1971 when U.S. exports were lagging, was that a tax break would stimulate more sales overseas. In theory, that would mean more U.S. jobs, busier factories, more tax money from other channels, an improved trade balance, a boost for firms competing internationally with companies whose home governments give them certain breaks.

The theory is one thing, but there is a great deal of debate about whether DISC actually works. The president says it does not and that it gives selected companies an unacceptable tax break.

Not surprisingly, the Treasury Department agrees. Its latest annual report on DISC, the 1976 report issued last month, said that U.S. exports rose rapidly between 1971 and 1975, from $43 billion to $107 billion.

"Practically all of this expansion, however, was due to factors other than DISC," the report said.

As might be expected, American companies have not been shy about taking the DISC tax break. Through last February, some 10,000 DISCs had been set up, in virtually every congressional district in the country.

They range from some of the largest, say a General Electric, to tiny manufacturing firms that have looked to DISC as a way of breaking into export sales.

But, according to the Treasury, the bulk of the tax benefits go to a relative handful of the nation's largest companies - firms that relied on export sales long before there was a DISC.

Obviously, any governmental move to recoup more than $1 billion of uncollected taxes is going to stir emotion. A Special Committee for U.S. Exports, made up of firms that get the tax break, was set up in 1975 when Congress was putting some limits on the DISC program.

When Carter, first as a presidential candidate and then as president, began talking seriously about phasing out DISC, the special committee geared up again. It has kept up a drumfire of pressure and rolled out a mountain of statistics aimed at justifying and retaining DISC.

One of the special committee's educational targets would be new congressmen - the Ed Jenkinses and the Jim Guy Tuckers - who hadn't been through the DISC fight before and whose votes would be important in staving off Carter's revision.

As things have developed, the special committee hasn't really had to bother with educating Jenkins and Tucker. The fight hasn't materialized and the general feeling around Ways and Means is that Carter's plan to phase out DISC is about as dead as a doornail.

Rep. Sam Gibbons (D-Fla.), one of the few anti-DISC members of the committee, said, "I think there are only four or five votes here for repeal of DISC. Once a tax loophole is in the law, it's hard to get it out. There's always somebody who can defend it."

"DISC is a turkey - no, it's worse. It's an armadillo. It is a totally useless animal," he said. "People around here are saying we ought to leave DISC as a 'bargaining chip' on international trade matters. When you do that, the fight for repeal is all over."

After they got to Washington, Jenkins and Tucker, freshmen on the committee, quickly learned a couple of important things about their tax-writing assignments.

For one thing, each learned that he had a smattering of DISC companies at home. Mail from the firms - perhaps inspired by the special committee, perhaps not - urged them to take a close and careful look at a tax break that was helping employ constituents.

Tucker reflected on that. "Generally," he said in an interview, "my position on any tax changes is that you have to show me . . . Our contacts with bankers in Arkansas reflect some concern about DISC.

"I think if you consider an end to DISC in a vacuum, that's one thing.But each portion of the reform proposals and the tax code affects another. Major tax changes a feeling that we might be able to tell people we'll leave them alone for awhile," Tucker said.

Translation: He hasn't made up his mind about killing DISC; some constituents would like to keep it; he's feeling no great pressure one way or the other; if DISC survives, it wouldn't be quite a disgrace. (He's also running for the U.S. Senate.)

Jenkins, a Georgia Democrat like Carter, thinks his president is a little off base in rushing to eliminate DISC from the tax code.

"I am convinced that DISC helps, but the degree of help is debatable. I have had some good reports from people in my district - people I trust - about the benefits of DISC," he said.

"We ought to eventually look to modifying it," Jenkins continued, "but it appears to me the timing of the president is not good. Each of the minute incentives we have combines to help our export business.

"Only one or two of the 23 counties in my district have a DISC, so it's not a political plus for me to support it. But if ever there was a time when we need to encourage exports, we need to do it now. I think if the president gave this to Bob Strauss, our trade negotiator, using elimination of DISC for bargaining, I think he could break down the barriers that other countries put in the way of American products, then' I'll say do awat with DISC."

Translation: He might support an end to DISC someday, but the U.S. government ought to be doing more now - either by tax incentives or by an energetic promotion program of some sort - to stimulate more exports.

The thoughts of Jenkins and Tucker, arrived at without any apparent special coaching, dovetail almost exactly with what the Special Committee for U.S. Exports has been saying all along.

And they dovetail with what most of the more senior members of Ways and Means have been saying about any large-scale tinkering with the tax code.

They've yet written the obituary for Jimmy Carter's proposal to repeal DISC, but it doesn't appear to have a very healthy tomorrow.