He is tough for the '80s, this man who would be president, just as surely as if he had ridden into the convention hall astride a white stallion, six-shooter cocked in readiness. He is taking aim at foreign devils in defense of the American Way.

"We've been running up the white flag, when we should be running up the American flag!" he declares. " . . . What do we want our kids to do? Sweep up around Japanese computers?

" . . . We have got to get tough -- and I mean really tough! -- with nations that use our markets but deny us their markets! the working-class crowd erupts in applause And I'll tell you today that if you try to sell an American car in Japan, you better have the United States Army with you when they land on the docks!"

Now they are cheering this man who wants to be America's next president. Is this Big John Connally of Texas? No, this is Big Fritz Mondale of Minnesota, the reconstitution of Walter F. Mondale, turning them on at the International Union of Electrical Workers convention in New York City.

Mondale has tried out his new tough-talk address before three labor groups so far, the sheet metal workers, the electrical workers, the steelworkers, and has won standing ovations each time.

This was no happenstance. Mondale is talking the tough line that the AFL-CIO leaders want to hear, and he wants them to hear it from him, because the labor federation will try to unite its traditionally fractured ranks behind one candidate for the presidency before the first caucus or primary of 1984.

Mondale says he believes that tough talk about how America's multinational companies must take a nationalist line, creating jobs for American workers as competitive foreign nations do, is a key to success in the 1984 presidential race.

He may be on to something. Anti-Japanese sentiment in Michigan is at its highest pitch since World War II, with diatribes against the Japanese and their auto industry by bitter, unemployed auto workers backed by vandalism -- broken windshields and slashed tires -- of Japanese autos in cities like Flint and Lansing.

Listen to Mondale, 1982: "Now, I'm not a protectionist, but I'm not a sucker. And I believe our country and its leaders and its negotiators simply must get much tougher in negotiations and say something like this: 'From now on it's going to be fair. If you want to close yourself off from our markets, then we're going to take steps to make certain our markets are not going to be available to you!' "

Remember Connally, 1979: "It's time we said to Japan: 'If we can't come into your markets with equal openness and fairness as you come into ours, you had better be prepared to sit on the docks of Yokohama in your little Datsuns and your little Toyotas while you stare at your own little TV sets and eat your mandarin oranges, because we've had all we're going to take!' "

Those Connally lines of yesteryear were recalled to Mondale as he was driving the other day between campaign stops in America's presidential heartland, New Hampshire.

"The difference between me and what John Connally was saying is that my objective is a more competitive international environment, in which we . . . are much more competitive," Mondale says. The distinction is not readily apparent from the rhetoric.

Mondale -- who in 1974 decided he did not have the burning desire, nor the Gallup rating, to make the drive for the presidency, and who then did time in the netherland of the vice presidency instead -- is out and running now. And he makes it clear that is very much his own man now.

Fight . . . Tough . . . Number One . . . The American flag. They punctuate his speech these days with the subtlety of a tympanist in a string quartet. Fritz Mondale is off and running for the 1984 Democratic presidential nomination armed with a tough new speech that matches his new determination.

"This was my speech," Mondale says. "As a matter of fact, some of my staff didn't want me to give it."

It is worthy of note that the American flag has made its way back into a liberal Democrat's liturgy.

"It's my flag, too," says Mondale. "That's right -- but the old-line liberals look down at that."

His rhetoric is newly toughened, Mondale explains, but his positions are not. "I have felt that way for a long time," he says, " . . . but it never came across . . . .

"What is different now is that the public sees it. I am trying to state a case that moves a country. I never talked to an image maker about this. I never talked to a pollster about it."

The image makers and the pollsters, meanwhile, have had something to say about Mondale, however. He has trailed Sen. Edward M. Kennedy (D-Mass.) consistently and considerably in the polls of Democrats' preferences for the presidential nomination. Kennedy gets about 40 percent, while Mondale lingers in the high teens, ahead of Sen. John Glenn (D-Ohio) and the rest.

But polls also are a reflection of the fate that befalls most vice presidents.

So, the surveys show that while Mondale has extremely high name recognition, the public does not know much about him or where he stands. Also, his appeal is more to centrist Democrats than is Kennedy's, and his negative ratings are much lower.

For these reasons, media and strategy expert David Garth, among others, rates Mondale as "the Democratic candidate with more potential than Kennedy" -- which is to say that for all his years in public office Mondale can still make of himself what he wants.

"I don't think the public, although they know my name -- I don't think that I'm yet seen in the light I will be when I am campaigning for president," Mondale says. "What does Mondale believe? What makes him tick? . . . What they know about me basically is history."

Mondale's recent history is his service as vice president to Jimmy Carter. When asked how this will affect his political future, Mondale carefullly threads his way through an answer.

"I've never ceased being grateful to the president," he begins. " . . . But it probably goes both ways. To the extent that people do not remember the Carter years with fondness, they think of Carter and Mondale as a team."

He has also heard the comments that he is not tough enough to be elected president. Not so, he says.

"When I ran for president in 1974, I got out because I felt I wasn't ready to be president. I am ready now." And to illustrate his firmness and determination, he offers an example from his vice-presidential days.

"I went to the Philippines, beat up on Marcos, and broke an eight-year deadlock . . . on that Subic naval base and Clark airfield," he says, referring to his talks there with President Ferdinand Marcos. "I didn't go and praise him for his love of democracy," a reference to his successor in the vice presidency, George Bush, who said just that of the Philippine dictator.

"This," James Johnson says, gesturing at a cluster of suites in the corner of one of those sprawling Washington law firms, "is Mondale Inc."

Since January, 1981, Mondale has been associated with the Washington office of the law firm of Winston and Strawn, which has been his operational base.

Mondale has already built a campaign organization that is admired by many party pros. It is centered around his political action committee, the Committee for the Future of America, which raises money for Democratic candidates and for Mondale's travels around the country, making speeches, making new contacts and renewing old ones, as he builds his own base of support while helping others.

Kennedy has a similar PAC. Both are similar to Reagan's PAC, the Committee for the Future of the Republic, and both echo the pioneering work in building off-season political IOUs by Richard M. Nixon in the mid-1960s.

Mondale has made two one-minute television spots, one in which he talks about Social Security, the other about unemployment. He has bought $8,000 worth of television time beginning today to show them in Minneapolis and San Francisco to raise money for his PAC. He is also making them available to Democratic candidates, for whom he will dub a personal endorsement.

"By the end of the year," says Johnson, "we'll be able to show that Mondale has had more impact on the 1982 elections than anyone else." Mondale's PAC will have spent $2.2 million by then, and Mondale will have campaigned for 95 candidates for Congress, 17 for the Senate and 22 for governor, in more than 40 states.

Mondale also has a list of advisers that reads like a sort of Who Was Who in Democratic administrations.

Mondale's public position is that he is still deciding whether to run for president. His advisers say he will announce his candidacy just after the first of the year.

Johnson, who served as Mondale's administrative assistant and has traveled with him for years, has emerged as the major domo of the upcoming campaign.

But the job of chief speech creator has been filled -- by Mondale. For months, even years, he has been held up to comparison with Kennedy, and his standing in the polls has shown little change for all his travels. Now he is staking his future on his new speech and direction.

"Nobody knows what's going to happen 18 months from now," Mondale says. "Except, if you are saying the right stuff, and you are on the right course, and you've got the right analysis, and after you've spoken . . . you see that is what the people want, then the polls will follow . . . . .

"There's a little thing called leadership here."

As Mondale's car negotiates the road from Nashua to Durham, he contemplates the political road ahead.

Victory, he says, is no longer enough.

"If I run for president, the only thing worse than losing is winning with no mandate," Mondale says. "I was around the president when we lost our mandate, and it is a horrible feeling. . . . You could just feel it slipping away . . . around 1978. When the president would give his national messages . . . they weren't interested in tuning in."

He speaks quietly now, reflecting on those last years of the Carter presidency he served.

"A president with no mandate. . . . You have all the accoutrements of office, but none of its powers.

"It is a form of hell."