WHEN Americans turned on their televisions to find the Senate Judiciary Committee's investigation of Clarence Thomas had preempted Geraldo and the soaps - and further discovered it was hard to tell the difference - some line of public contempt for public officials was crossed.Few expected the Thomas confirmation hearings to be a feast of reason. But they were unprepared for an important constitutional process to be conducted with all the decorum and comity of professional wrestling. All this came hard on the heels of bounced House checks, another midnight pay raise, as well as a Keating Five investigation that looked suspiciously like a whitewash. In the eyes of many Americans, the problem is not the process, but the entrenched and distant politicians who operate it. The vehicle for change that many have chosen, fueled by outrage, is term limitations. Some politicians indignantly describe the proposal as unfair - to constituents, of course. "Some very good men and women will be forced to leave," they complain. Some political commentators attack the idea as "a simplistic and hasty answer to a complex problem." Term limits were in fact proposed at the constitutional convention in 1787. "Roger Sherman of Rhode Island," say the convention notes, "summed up the feeling of many delegates when he commented that Congress should be made up of 'citizen-legislators' who through the principle of rotation in office would 'return home and mix with the people.' By remaining at the seat of government, they would acquire the habits of the place, which might differ from those of their constituents." Thirty-one states now limit the terms of governors. Congress had few qualms about applying term limits to the president. The idea is not the creation of demagogues, swept forward in a brushfire of populism. It is a serious proposal with serious aims. The first goal is to reduce the concentration of political power that comes from seniority. Often a lifetime of accumulated influence is used to secure larger and larger portions of public expenditure for purely local interests. It is a problem illustrated when a senator of distinguished service - and immense power - attempts to transport the federal government bit by bit to the rolling hills of West Virginia. Second, term limits would encourage certain attitudes among legislators. It would no longer make as much difference how many special interests they managed to please or how much pork they delivered back home. No matter what they did, public service would not be a career. And this might provide the freedom to act with greater integrity. What about objections to term limits? Such as: Term limits will increase the power of congressional staff. Inexperienced legislators, in this view, will rely on a permanent and influential cadre of policy experts. But senators tend to bring new staff with them - people they trust, often from their own state. Term limits are just as likely to limit the tenure of powerful staffers who would lose their long-term patrons. Term limits will eliminate some talented and experienced legislators. This is undoubtedly true. But our pressing problem is not a lack of talented men and women to take the places of those who leave; it is a surplus of entrenched power. Term limits are simply unnecessary. Critics note that in the last Congress 67 percent of the members had served less than 12 years. But the attitudes and actions of Congress are set by its leadership. The average seniority of committee chairmen in the House is 26 years. The average in the Senate is 20 years. To practice what I preach, I've made a public commitment to serve no more than two full terms in the Senate, if the people of Indiana grant me a second one. This is a limit. But it is also a source of liberation - the liberation of the lame duck. A Congress of lame ducks might begin to concentrate on policy, not the demands of a career or the opinions of special interests. Politics has been called the lifetime pursuit of a swiftly darting spotlight. But term limits would force public servants to face life beyond the spotlight - a life lived under the laws they've written and among the people they were elected to serve.