Miami — Walter Mondale, talking with reporters the other day, used the word ''fight'' four times within one minute. It now appears, after his double losses in New Hampshire and Maine, that Mr. Mondale is in the political fight of his life. It's the kind of rough-and-tumble battle that Mondale has avoided most of his political career.
Gary Hart's 51-to-44 percent victory over Mondale in the Maine caucuses gives the young Colorado senator just what he needed - a fresh burst of support prior to the Super Tuesday vote, March 13, in nine states. It's exactly what Mondale had hoped to prevent by sending his best political operatives to Maine.
The sudden shift in the political tide will be a supreme test for Mondale. He will have an opportunity to show the country that he has the kind of political toughness and desire it takes to win when the pressure is on.
To turn things around, Mondale is trying to overcome a number of problems with his campaign that have surfaced during the past two weeks. These problems can be summarized as follows:
1. Mondale is seen by many voters as too close to ''special interests,'' especially big labor.
2. Mondale represents experience, the public believes, but he has little to offer in the way of ''new ideas,'' which is the theme of the Hart campaign.
3. Mondale is considered less supportive of arms control than Hart.
4. Mondale, according to voter surveys, would do less to cut red tape and waste, or to reduce the deficit, than Hart.
These are powerful issues, and they clearly have the Mondale team worried. In recent speeches in New England and here in the South, Mondale has gone out of his way to address some of these perceptions.
Speaking to a convention of AFL-CIO leaders from the South here in Miami over the weekend, Mondale shouted: ''You want a hot speech? You're going to get it.''
On the special-interest charge, he said:
''Is it a special interest to stand up for people who are hungry? Is it a special interest to insist that the next generation of our children be the best educated in the history of our country? . . . Is it a special interest to say that when you go to work you shouldn't risk your health and your very life? . . . Is protecting the environment a special interest? Is protecting civil rights?''
Such arguments are meant to rally the many activists in the Democratic Party, and deflect barbs from those who charge that Mondale would be beholden to the AFL-CIO once he got into office. That argument is said to have hurt Mondale badly in New Hampshire. ABC-TV exit polls there found only 2 percent of the state's voters admired Mondale for his ''independence,'' compared with 59 percent for Hart.
On ''new ideas,'' the Hart theme, Mondale said:
''The question is not whether an idea is new or old. The question is, is it right, or is it wrong? Will it work, or will it fail? . . . Reaganomics is a new idea, and it's as lousy as it can be.''
Since his first defeat, Mondale has shown more spirit, more fire, than in earlier speeches and debates, when he cautiously tiptoed around hot issues. He explains that earlier he was trying to prevent any split within the party.
Analysts, however, are not so sure that's the whole story. Among those who follow politics, one perennial doubt about Mondale has been whether he had the inner resolve that it takes to win a hard political fight. Throughout his career , he has been blessed with an almost effortless rise to power.
Mondale got his first big break in 1960 when Gov. Orville L. Freeman appointed him as Minnesota attorney general.
Mondale then moved up to the US Senate in 1964, again by appointment, when he filled the unexpired term of Hubert H. Humphrey.
The next step up the ladder came in 1976, when Jimmy Carter tapped him as vice-president. Mondale moved into that job after Mr. Carter and his tough political crew had done all the hard work.
Even this year, when Mondale stood far out front in the polls, he got there in large part because he was the choice of the Democratic establishment. Labor unions, teachers, liberals, and supporters of Edward M. Kennedy combined with Mondale supporters to rewrite the primary and caucus calendar in a way that tilted the contest toward Mondale.
Despite his setbacks, Mondale appears vigorous and ready for the struggle. He describes what he must do in pugilistic terms:
''We have to slug it out in every state of the Union and see it for what it is. It's clearly a two-man race, and it is very close.''