When the Polish government cracked down on its labor movement, tossing its leaders in jail because they dared to agitate for political freedom, it moved President Reagan to anguish and action.

"To underscore our fundamental opposition to the repressive actions taken by the Polish government against its own people, " the president last week suspended food shipments, aviation privileges, fishing rights, technology transfers, credit and other "major elements of our economic relationships."

South Africa, whose dealings with its black majority have made it the international standard for political repression, has moved recently to clamp down on its struggling black labor movement, including the detention of its key leadership. The government there has also moved against the South African Council of Churches, in apparent retaliation for the council's support of political dissident.

The most obvious reaction of the Reaagan adminstration has been to strengthen economic ties with South Africa.

The contrast, says the Rev. Jesse Jackson, is not merely ironic but dangerous to American interest.

"We do not disagree with what the administration is doing with regard to Poland," he sid in an interview. "We at PUSH have taken a strong position against oppression in Poland. But we insist that human rights must be measured by a singleyardstick."

Nor is it just the Reagan adminstrationn that is applying the double standard, Jackson said. "The AFL-CIO has held rallies in support of the Polish workers But there is no talk of not loading or unloading ships from south Africa. Indeed they enjoy the benefits of trade with South Africa.

"The ultimate culprit is the press itself, with its incredibly vigorous hype of the Polish situation. If the media put that kind of attentionn on South Africa for just 10 days, this nation, which still does not fully understand the level of oppression there, would rise up in moral outrage."

The ironies abound--sometimes involving race, sometimes anitcommunism, sometimes the government's own priorities. "We are making special provision for refugees from Poland, because they are escaping communism."Jackson said. "But at the same time, former supreme court justices and lawyers and bankers from Liberia who are already here can't get green cards that will allow them to go to work. Haitians, who are fleeing repression and poverty of the worst sort, are faced with a choice ofbeing tossed into stockades are becoming food for sharks.

"Is what is happening with the air-traffic controllers really so different from what is happening in Poland? In Poland, the government got tired of illegal union protests, and they did to Solidarity what Reagan did to PATCO using the army to replace workers and then using the media to humiliate them."

Still the adminstration's disparate reactions to Warsaw and Pretoria provide the most striking irony.

While Regan, in his nationally televised speech last week, said he would use the carrot-and-stick approach in seeking to resolve the Polish crisis, he has abandoned the identical approach of the Carter administration in dealing with South Africa. Reagan has cut trade relations with the Polish government and threatens simialr action with regard to the Soviet Union, which presumably is orchestrating the Polish crackdown. But with regard to South Africa, the official U.S. policy is one of carrots without sticks, and America remains South Africa's o. 1 trading partner.

"Our ease with racism and our obsession with communism is perviertin our foreign policy," Jackson said. "[Israel's prime minister Menachem] Begin raised the curcial question in his reaction to our criticism of Israel's annexation of the Golan Heights. He challenged our moral authority to oppose what he is doing, and he is right. You cannot gain respect unless you have the believability that comes from consistency.

"The attempt to give tyranny two definitions won't work."

And that is precisely what the Reagan administration is attempting. It tries to distinguish between refugees from political tyranny and those ho would flee tyranny that is merely life-and-death economics, embracing the former and leaving the latter to drown at sea.

Does the administration suppose that the Polish ambassadors to the Washington and Tokyp are seeking asylum here because they don't like communism? The problems confronting both Solidarity and the black trade unions of South Africa have less to do with theoretical forms of government than with living standards,f-determination and freedom from oppression.

The administration sees it very clearly when the oppressors are communists but not when the oppression is from the right.

It is, as Jackson says, an attempt to give tyranny two definitions. And, as he warns, it cannot work--at least not for long.