Until 1968, George McGovern was a well-liked but relatively little-known Democratic senator from the small agricultural state of South Dakota.

Then McGovern, with the help of other senators and lobbying organizations representing the poor, got the Senate to create a Select Committee on Hunger and name him chairman. Overnight he acquired a staff, a title, a rostrum. In a series of brilliantly planned hearings, he became known nationwide as the champion of the poor and the hungry. It helped him win the 1972 Democratic presidential nomination.

Frank Church (D-Idaho) was well-known in the Senate but had little national recognition until 1972, when he was named to head the Senate Subcommittee on Multinational Corporations.

Sensational hearings, well-publicized in the press and on televsion, revealed undercover payments by American corporations to foreign officials. Over the TV tube, Church's face and voice came into every living room.

These examples, which could be multiplied many times, illustrate one of the reasons why it's a wonderful thing to be a committee of subcommittee chairman in the Senate. They also help explain what underlies the current Senate battle over reorganization. It's not the vision of a more rational committee system. It's the reality of getting and keeping power.

When the Senate Rules Committee voted recently to meld the hunger unit into the Agriculture Committee McGovern promptly vowed on all-out fight on the floor. Church has been fighting against yielding control over international economic policy to the Banking Committee. Throughout consideration of the reorganization plan, efforts by other chairmen to preserve their turf have been evident.

The opportunity for good publicity is only a start of the good things that come to a chairman. The first thing he gets is staff - lots of it. The Senate Committee on Aging, which the Rules Committee has voted to abolish, has 13 staff members for the majority. In effect, they all work for Church, who happens to head this unit too.

The Judiciary Committee and its subcommittees have about 200 staff members, many of whom work for Chairman James Eastland (D-Miss.). But Eastland gives the chairman of each subcommittee complete control over its majority staffing. As chairman of the Antitrust subcommittee, the late Philip A. Hart (D-Mich.) had about a dozen professional staff there working for him. Former Sen. John V. Tunney (D-Calif.), who headed the Constitutional Rights Subcommittee, had direct control over most of the staff of 20.

Having such staff enables a senator to get a lot done. He can assign staffers to projects he likes. They produce the materials that he reads aloud on the floor, at hearings, over television. They do the day-to-day work that can make him a star.

Sometimes a chairman will stash away some politicial-type employees in a committee slot. A Washington Post study two years ago turned up nearly half a dozen Senate Commerce Committee personnel who were basically old retainers of Chairman Warren G. Magnuson (D-Wash.) or even doing political casework for him while on the committee payrol1. (They're gone now.)

When former Sen. Vance Harke (D-Ind.) was chairman of Veterans' Affairs, one of the committee rooms appeared to be set aside from the rest, and several committee secretaries and clerks said it was Harke's private pressroom, used not for committee matters but for his Senate office business. The room had political district maps of Indiana pinned all over the walls, and piles of clippings on Indiana politics. The man using it was paid by the committee and at that time was listed in some Senate manuals as Harke's personal press secretary.

As the staff director of a major committee said, "Technically the staff works for the whole committee, or for the majority or minority members as a whole. In pratice, if yoy are chairman, the staff responds to you. You set their priorities, you control what they work on."

That gives the committtee chairman a lot of extra legislative influence. Studies are performed and bills are drafted with a spin toward his position.

On top of that, the chairman in fact controls the flow of committee business. He scheduled meetings, hearings, voting sessions. He can delay, stall or speed up a bill. If backing it means good publicity, he can become its floor manager and champion. If it would be bad publicity, he can give it to another member and avoid the blame. "You can shove off the hot potatoes to someone else," said the staffer.

A chairman has other benefits. The leadership consults him on matters in his jurisdiction. The President consults him and courts his favor, and gives little favors back.

Senate Majority Leader Robert C. Byrd (D.W. Va.) has described how to use this technique. President Johnson wanted some money for a project over which Byrd, as an Appropriations subcommittee chairman, had jurisdiction. Byrd sat on the request. Time passed Johnson got restless. "What's holding it up, Bob?"

Byrd finally revealed that he wanted a certain federal research facility installed in West Virginia, but the Johnson administration hadn't agreed. Byrd told Johnson he was spending so much time worrying about that, he hadn't had time to take care of the matter Johnson was interested in. Soon after, Byrd got his facility, and Johnson in turn got what he wanted. That's he kind of leverage a chairmanship brings.

It also provides leverage with other senators or House members.

A staffer, now in the Senate, recalls, "I was standing with (ex-Rep.) Ken Gray (D-III.) the day he found out he was to become chairman of the House Public Works Building Subcommittee. I think the former chairman had just died or retired.Gray leaped up and danced a little jig and said, 'I've got something every member of the House wants."

"That subcommittee had jurisdiction over construction of federal buildings in various parts of the country. The power to help give them these buildings gave him the power to get things back from other chairmen in return, things he wanted for his own district, little legislative favors."

The extra legislative spin and influence you get from being chairman also gives you power over people who want something from your committee. They are then willing to do things for you, like give you campaign money, support your re-election.

Hartke for years was chairman of the Senate Commerce Surface Transportation Subcommittee. His contribution list is loaded with such items as $1,000 from the president of Coyote Truck Lines. $2,000 from the Transportation Political Education League. $2,500 from the Seafarers Political Activity Division, $4,300 from the Burlington Northern Employees Voluntary Good Government Fund. $200 fron the board of directors of Atlas Van Lines.

A committee or subcommittee chairman can schedule hearings in his own state, which Magnuson and many other have done. He can go on junkets ("drunkers," one senator has privately called them) with the committee paying the bill at his say-so. One year Hartke and a secretary were listed as having traveled to western Europe. Greece, Egypt and Israel on behalf of the Veterans' Affairs Committee, at a cost of about $8,000. John Sparkman (D-Ala.), now chairman of Foreign Relations, is one of the champion junketeers, and the late Allen J. Ellender (D-la.) was famous for his annual round-the-world junkets when he headed the Agriculture and Appropriations committees.

Benefits from a chairmanship, however, depend on getting the right one. Some carry little or no extra staff and may impose responsibilities the senator doesn't want.

When Daniel K. Inouye (D-Hawaii) was finally able to shed the chairmanship of the District of Columbia Appropriations Subcommittee, he came rushing out of the room with a huge smile and his arm raisedin triumph, shouting happily, "free at last! free at last!"