Mi-i-i-ster Speak-e-e-er!

TWO hundred sixty Democrats were milling about the eastern half - the Democratic half - of the House of Representatives last Monday. But James C. Wright Jr. stood in the back of the empty Republican side of the chamber, far removed from his colleagues. For 10 years Mr. Wright had served as House majority leader. According to tradition, that put him on deck to be the next Speaker of the House. Yet Wright - always loyal, usually fastidious in his pronouncements - had been careful not to seem smug about his career prospects and not to upstage the Speaker of the House, Thomas P. (Tip) O'Neill Jr.

``I don't want to be speaking for the Speaker,'' Wright would protest. ``As long as I'm the majority leader, the Speaker won't need a food taster.''

Wright's circumspection was about to pay off in his election as the the 51st Speaker of the House, commencing a new congressional era. The 63-year-old Texan was off at the far end of the chamber, quietly making some final changes in his acceptance speech. A few moments later his colleagues dispensed with the customary election by secret ballot and elevated Wright to the speakership by acclamation.

The action was no surprise: Since Mr. O'Neill had announced his impending retirement two years ago, Wright's candidacy for the speakership had generated the momentum of a freight train - so much so that no one bothered to oppose him.

During 31 years as a congressman from Forth Worth, Wright quietly did the things one must do to climb the rungs of influence in the House. The effort culminated in a 1976 surprise victory over two more-senior rivals to become the majority leader.

President Reagan and the Republican Senate took their places in 1981; the House of Representatives became the only Democratic stronghold in the government, and Wright became ``Tip'' O'Neill's man Friday while the Speaker led the opposition.

When the 100th Congress convenes in January, the Democrats will be astraddle the Capitol, retaining their huge House majority (now 258 to 177) and having taken control of the Senate, 55 to 45, in the November election. Democratic leaders have a chance to challenge the President with the sort of legislative initiatives they could only dream of when the Republicans controlled the Senate.

House Democrats are banking on Wright's seizing the opportunity. Members of Congress and congressional observers say Wright is more interested in the details of legislation than was O'Neill, whose strength lay in broad political strategy. They expect that the details of many bills coming from the House will bear Wright's mark to a much greater degree than they did O'Neill's.

``Jim Wright knows as much about the levers of this place as anyone,'' says House majority whip Thomas Foley (D) of Washington, who will succeed Wright as majority leader when Wright officially becomes Speaker.

Like O'Neill, Wright is known as a fierce partisan, with a penchant for leaping into political confrontations with abandon. He was one of the most vocal advocates of an attempt by House Democrats to repeal the third year of the 1981 Reagan tax cut. The House passed the repealer, but not the Senate.

Wright has been a consistently vocal foe of Reagan administration attempts to cut social spending and increase the military budget. He broke with most of his colleagues in the Texas delegation to seek defeat of aid to the Nicaraguan contras.

But many Republicans say they would rather deal with Wright than O'Neill, if only because Wright has a reputation as an indefatigable worker who seems to be better versed on the issues than was O'Neill. ``He is the quickest study I know,'' says Craig Raupe, a former Wright aide and close friend, now a Washington lobbyist.

Says House minority leader Bob Michel (R) of Illinois: ``Jim will be aggressive, but I think fair.''

Wright himself says, ``I don't have in mind a grandly ambitious shopping list of things to do, but I do think we have a responsibility in Congress to come forward with our own agenda. We are not just supposed to react to the President.''

He will reintroduce the comprehensive trade bill, attacked by the administration as brazenly protectionist, and revive the Clean Water Act, vetoed last month by Reagan. Other matters on Wright's agenda: welfare reform and an overhaul of the farm subsidy program.

Perhaps the clearest sense of the independent tone Wright might set came after his election as Speaker, when he told reporters that he thought the tax cuts for higher-income taxpayers as set out in the tax-code overhaul adopted earlier this year ought to be delayed. It was a daring pronouncement, and Wright's colleagues in the Democratic leadership stifled looks of horror. They knew what was coming: Within 24 hours, the proposal had elicited howls from Republicans and conspicuous discomfort among Democrats, particularly in the Senate.

The episode underscores a political reality Wright will have to accept as Speaker. Rep. Dick Cheney (R) of Wyoming says, ``He's not going to be able to be a free agent and enunciate policy and make it stick if that's not where his troops want to go.''

The new Speaker acknowledges that he will have to work closely with the newly empowered Democratic leadership in the Senate if he hopes to get much accomplished. Wright says that fact ``places upon the [House] leadership a different responsibility to work in tandem with the leadership of the Senate.'' But he calls it ``an opportunity more than a problem.''

In fact, Wright has an excellent working relationship with the incoming Senate majority leader, Robert Byrd (D) of West Virginia. The two have already begun to confer on an almost-weekly basis.

Wright's dealings with Senator Byrd and the Senate Democrats in the center may be helped by the fact that he is considered to be of a more moderate philosophical stripe than O'Neill, who represented one of the most liberal districts in one of the most liberal states in the country. Wright hails from a district that went for Reagan in both 1980 and '84 and has strong oil and gas interests.

Some observers say Wright is closer to the ideological center of the House Democratic Caucus than O'Neill and thus may not become as prominent a national spokesman for the party as was the Massachusetts liberal. He may also encounter a degree of resistance to his House leadership.

Some people find Wright's adrenal personality jarring, especially next to O'Neill's avuncular style. ``Jim Wright's not a guy that has a lot of friends on this side of the aisle,'' says a Republican member of Congress. ``Clearly, Tip was a much-loved figure.''

Late one evening at the end of the congressional session, the member recalls, when House members had nearly finished debate on the omnibus drug bill and were preparing for a vote, Wright asked the presiding officer if he could make a final, 10-minute statement on the floor. When the presiding officer asked the chamber if there were any objections, hisses and catcalls echoed through the chamber. Wright backed down.

``I was fascinated that they treated him just like any member, not like the person who was going to become their Speaker,'' the Republican member says. ``Tip wouldn't have got that kind of treatment, and I don't even think Bob Michel [the GOP minority leader] would have.''

Wright's temper is legendary. He is reputed to be thin-skinned, and to accept criticism with difficulty. Twice, he has nearly come to blows with colleagues on the House floor.

He is known to explode at colleagues in private meetings. But he cools down as quickly as he heats up. ``He always assumes it is his fault,'' Mr. Raupe says. And so Wright usually follows his outbursts with effusive apologies.

``Jim needs to watch his temper,'' says O'Neill. Wright does not disagree: ``I think he's right, no doubt about it.''

Some Democrats are also concerned that Wright does not project the image they want on television. It has been suggested that he is more a master of the 30-minute harangue than the 30-second sound bite. On the House floor, a Wright performance can be excessive, or stirring, depending on one's perspective. ``You watch him and you know when he's going to get partisan,'' Republican leader Michel said in 1984. ``The eyebrows start to rise. The voice begins to stretch out. And the Republicans say, `Snake Oil is at it again.'''

Others have a different reaction. ``Jim can go to the [House floor] and make a speech and change a dozen votes,'' says O'Neill. ``That's a talent.''

Wright's persuasive powers will be taxed to the utmost in his new position. The Speaker has enormous power to decide what legislation reaches the floor and when. But ultimately his power, and the power of the leadership he heads, is of a collaborative nature. He must persuade and cajole committee and subcommittee chairmen to his point of view, and he must corral members of the House, who tend to be better educated and more independent-minded than their predecessors of a generation past.

Many Democrats think Wright might have the will to exercise greater discipline over House members than O'Neill did. But ``it's a tall order,'' says House Energy and Commerce Committee chairman John Dingell (D) of Michigan. ``Have you ever tried to discipline 258 Democrats?''