"A powerful agent is the right word," wrote Mark Twain in 1906. "Whenever we come upon one of those intensely right words . . . the resulting effect is physical as well as spiritual, and electrically prompt."

Amid the drone and drivel of the millions of words uttered on the floor of Congress in 1982, painfully few nouns, few adjectives or few adverbs sparked the physical, spiritual and electric effect that Twain described. But a disproportionately high percentage of those rare yet intensely right words that electrified came from the lips of House Majority Leader Jim Wright of Texas.

It was Wright who, last September, stood in the well of the House with his bushy eyebrows pointing upward like the tail fins on a 1961 Buick and asked his colleagues whether they were "going to let the White House lead them around with a ring in their nose like a prize bull at the country fair." Wright paused dramatically and the House--for a brief moment resembling the British House of Commons--broke into a divisive chorus of applause, groans, murmurs and catcalls.

During another of last year's interminable budget debates, Wright stood before the House brandishing the 1981 budget bill (Gramm-Latta) and a computer printout listing the 436 laws it repealed or amended. The question, Wright declaimed, was "whether the Republican minority (would) again get to package all of their grand array of proposals into one amorphous whole where the specific afflictions of the public can be hidden and advertise all of it under some nebulous, euphonious title such as"--here the Majority Leader dropped from a baritone to a dramatic basso profundo--"President Reagan's Program."

A third example of the Wright words in action can be drawn from the tumult on the House floor during the waning days of last month's lame- duck session. Rep. Silvio Conte (R- Mass.) had just quoted President Reagan as saying he didn't "give a damn" if his threatened veto of a jobs bill forced Congress to stay in session on Christmas Eve.

Dripping sarcasm, Wright rose to say, "I cannot conceive of the president of the United States making a statement like that. Certainly the gentleman is misquoting him." No, said Conte, it's an accurate quotation. This sent Wright into a carefully orchestrated tirade against the president: "Who does he think he is?"-- elongating the sibilant sound of the two-letter verb. "He isn't supposed to become Big Daddy, the dictator who writes the legislation."

Performances like this help explain why Rep. James Howard

(D-N.J.) calls Wright, "the

best public speaker in the nation." A poll of House members in 1980 by U.S. News selected Wright as "the most persuasive in debate." Rep. Jack Brooks (D-Tex.), who has known Wright since they served together in the Texas legislature in 1947, said, "If Jim got a tent, a moneychanger and a good song-leader, he'd be competing with Billy Graham."

Wright's rhetoric is not as florid as that of Rep. Guy Vander Jagt (R- Mich.), the keynote speaker at the 1980 Republican National Convention. (Wright himself modestly describes Vander Jagt and low-key Democratic humorist Mo Udall as the two "best orators" in the House). Nor is the majority leader anywhere near as theatrical as former representative Daniel Flood (D-Pa.), a one-time Shakespearean actor who came complete with a waxed mustache and black cape, and was a congressional institution for a generation until he resigned ensnarled in scandal in 1980. But former Texas Democratic representative Phil Gramm, a one-time Wright prot,eg,e who resigned Jan. 5 to seek reelection as a Republican, is not far from the mark when he says of the majority leader, "His oratory would be at home on a platform with William Jennings Bryan."

Jim Wright, 60, came to the House in 1955, at a time when Congress was dominated by the persuasive styles of two fellow Texans, Speaker Sam Rayburn and Senate Majority Leader Lyndon Johnson. He is part of the last generation of congressional leaders who entered politics before it became a subsidiary of the television industry. As the leading floor spokesman for House Democrats, Wright's nontelegenic style is both a strength and a weakness.

"The real liberals in our party don't hear enough raw meat," said a well-respected Capitol Hill aide close to the House Democratic leadership. "When Wright waves the Gramm- Latta bill in his arms, it turns on the whole House. He makes it harder for Democrats to go against the party. He builds up passions. But it doesn't work on television. You can't be theatrical on TV. It bugs the hell out of me that Wright can't do better on TV."

Wright firmly believes that well- chosen words in the well of the House can make a difference: "I don't agree that no votes are gained or lost in debate. If you can catch a tide at the right moment, you can ride the crest of the wave."

But in a Congress dominated by special interest groups and television appeals by the president, there are those who wonder if Wright is not just preaching to the choir. "In the four years I've been in the House, I don't think I've seen a situation where a speech by Jim Wright-- or anyone else--made a difference on a floor vote," observed Rep. Martin Frost (D-Tex.). "I doubt if that many minds are changed on the House floor," said Rep. John Paul Hammerschmidt (R-Ark.). But Hammerschmidt added, "If they are changed, Jim presents his case as well as anyone in the House."

Novelist Ward Just has written about congressmen "whose words have weight."

Often the words that have

the most heft are spoken in private, a few murmured sentences in the House doorway before a vote or a little subtle persuasion over late-night drinks in a Capitol office. In one-on- one sessions like these the young Jim Wright was heavily influenced by Sam Rayburn and "his fundamental persuasiveness bereft of verbiage but heavy with thought that could hit you where you live."

As a new legislator in 1955, one of the first issues confronting Wright was whether to vote to raise congressional pay from $17,500 to $22,000 a year. Wright recalled he was inclined to vote against the bill when Rayburn called him in for a chat: "Mr. Rayburn frowned that businesslike frown of his and said, 'Jim, if you vote against the pay raise, it's for one of two reasons: either the job you sought isn't that important a job, or you're saying that you aren't a big enough man for the job.' " Wright voted for the pay raise.

Almost 30 years later, Wright himself is a master of this behind-the- scenes persuasiveness. Wright claims that he doesn't use threats or dangle favors like choice committee assignments or help in raising campaign contributions before recalcitrant legislators. "I don't like to think that I get things done that way," he said, "but I am aware that others may react with the thought in mind: 'It doesn't hurt to be on the good side of the majority leader.'"

Early in 1981, Rep. Kent Hance (D-Tex.) won a seat on the House Ways and Means Committee with the help of Jim Wright. That same year Hance defied the Democratic leadership and became a co-sponsor of the Reagan tax-cut bill. A few months after the tax bill passed Congress, Wright came to Hance with a little quiet counseling. "He talked about how important for me it was not to stay too close to the Reagan administration," Hance said. "He let me know in a roundabout way that he wasn't mad at me, but he was disappointed. He made me feel sort of bad."

This ability to convey disappointment tersely, to make a junior colleague feel "sort of bad," was one of the lessons that Sam Rayburn taught Jim Wright. You could hear the echoes as Hance recalled Wright's words: "I felt like you had a lot ofgs Bryan."

Jim W leadership qualities for the Democratic Party, and I told people you did. And I've been criticized because of it."

But to be effective, congressional persuasion must also hold out the hope of redemption. According to Hance, Wright also said that "he didn't think that I had alienated myself to the point that I wouldn't have a future in the party. He told me to look at the big picture and to think about the long run. He said for me to think about the friends who helped me." Parenthetically Hance added, "He didn't have to say the friends who got me on Ways and Means. That was implied." These soft sentences, Hance said, "had more effect on me than any kind of browbeating would have had."

Jim Wright summarized his own style best when he said a while back that a majority leader must be "part evangelist, part village priest and part prophet."