Standing across from the Statue of Liberty, Ronald Reagan told a diverse and cheering ethnic audience today that Carter administration had "betrayed" the aspirations of American working people.

"The Lady standing there in the harbor has never betrayed us once," declared a shirt-sleeved Reagan to a Labor Day picnic crowd in Liberty Park. "But this administration in Washington has betrayed the working men and women of this country."

The Republican presidential nominee alternated attacks on the "sorry record" of the Carter administration with celebration of the immigrants who came to nearby Ellis Island and "helped to build that magnificent city across the river . . . and spread across the land building other cities and towns and incredibly productive farms," Reagan also spoke glowingly of the "brave workers in Poland" and their apparently successful fight to establish free trade unions over the opposition of the communist regime. And at the end of his speech be introduced Stanely Walesa, a Jersey City lumberyard worker who is the father of Polish strike leader Lech Walesa.

Reagan's main contention before his predominantly working-class audience was that Carter had promised much and delivered little to American working people.

"The Carter record is a litany of despair, of broken promises, of sacred trusts abandoned and forgotten."

Continuing to insist that the United States is in "depression" instead of a "recession" as President Carter maintains, Reagan said:

"Let it show on the record that when the American people cried out for economic help, Jimmy Carter took refuge behind a dictionary. Well, if it's a definition he wants, I'll give him one. A recession is when your neighbor loses his job. A depression is when you lose yours. Recovery is when Jimmy Carter loses his."

As has been customary at recent Reagan events, there were a few hitches in the campaign today.

Despite the busing in of several hundred people representing a dozen ethnic groups, the crowd was relatively small -- perhaps 1,000 people. The sound system did not work properly. And while Reagan repeatedly referred to the "great Lady looking on" at the proceedings, it was the backside of the Statue of Liberty that actually overshadowed the Liberty Park picnic.

Nevertheless, Reagan aides considered the event the most successful one in three weeks of campaigning during which the GOP nominee has raised as many questions about himself as about his Democratic opposition.

Today, Reagan stuck to a script that was a well-worn and sometimes biting attack on Carter administration economic policies. The indictment listed by Reagan included 8 million unemployed workers, whith black unemployment at 14 percent, inflation of 18 percent in the first quarter of 1980, four consecutive federal deficits and the highest interest rates since the Civil War.

Reagan said that if the president thinks there is no depression he should "go to the unemployment lines and lecture those workers who have been betrayed on what is the proper definition for their widespread economic misery.

"Human tragedy, human misery, the crushing of the human spirit," Reagan said. "They do not need defining -- they need action. And it is action in the form of jobs, lower taxes and an expanded economy that -- as president -- I intend to provide."

After listing promises that he said Carter had broken, Reagan suggested that the president might break another one -- his promise to debate Reagan in the fall campaign.

"I look forward to meeting Mr. Carter in debate, confronting him with the whole story record of his administration -- the record he prefers not to mention," Reagan said. "If he ever finally agrees to the kind of first debate the American people want -- which I'm beginning to doubt -- he'll answer to them and to me."

The Reagan speech was carefully targeted to an audience the candidate's strategists believe could be decisive in the 1980 election. Basically, these are blue-collar workers, especially those of Eastern or Southern European descent, who live in the urban centers of the Northeast and Midwest.

Hudson County, where Reagan spoke, is a Democratic bastion that Carter carried with 55 percent of the vote in 1976. However, Richard Nixon overwhelmingly carried it in 1972 after a campaign directed at normally Democratic ethnic voters. The ethnic groups present today included Italians, Poles Hungarians, Ukrainians, Latvians. Lithuanians, Estonians, Nigerians, Cubans, Haitians and Taiwanese.

But the advance men who set up the event are of Irish decent and the largest of the many ethnic signs here proclaimed: England get out of Ireland."

There was also a sprinkling of pickets supporting the Equal Rights Amendment, which Reagan opposes. One picket waved to Reagan's daughter. Maureen, an ERA supporter, and yelled, "Stay with us. Maureen."

She grinned, gave a thumb-up sign and called back: "I will. Hang in there, baby."