When Congress voted last year to shut off money for "covert" operations in support of the Nicaraguan counterrevolutionaries (contras), the general sense was that the issue was dead. But there was Ronald Reagan on a recent Saturday radio show and at his subsequent press conference -- on a landslide, reelection roll, giving free rein to the same old ideological drives and impossible dreams. Once again, they bore no relation to anything that could pass for a realistic Nicaraguan policy.

So the first instinct of congressional critics was to conclude that it won't work any better this time than the last. But the sheer force of the president's renewed crusade is giving some of the opposition second thoughts. At the very least, the issue is going to be front and center in Congress this year. 'f the president really wants to put on a full-court press," says one congressional opponent, "it's going to be a close, hard fight."

Last year, Reagan sought unsuccessfully to cajole Congress by reassurances that (never mind the occasional rhetorical excess) all he really wanted to do was "inconvenience" the Sandinistas "until they quit" exporting their revolution. He promised Senate Majority Leader Howard Baker that the United States was not trying to "destabilize or overthrow the government of Nicaragua." No such reasoned restraint is in evidence this time around.

His radio chat was vintage, pre-presidential Reagan, full of the romance of revolutions -- ours, and now that of our "brothers" in Nicaragua. To deny aid to these "freedom fighters," Reagan argued, would be to "betray our centuries-old dedication to supporting those who love freedom. This is not only legal, it's totally consistent with our history."

Actually, it's neither. The president didn't seem to know of the Boland Amendment, when asked about its prohibitions on aid for the contras. His response was a reference to "proposals" in Congress that he thought "lacked a complete understanding of what is at stake there and what we're trying to do."

Congress knows the stakes. It knows the nature of the Sandinista regime. The debate in Congress is not over whether the Sandinista presence is a bad thing but over what to do about it.

So when the president says Congress doesn't understand what "we are trying to do about it," he is getting to the heart of what the forthcoming debate is going to be about: the president's double-talk about practical objectives as distinct from optimum desires; the means to be employed. Congress questions the basis in international law and the moral grounds for U.S. intervention. It questions, as well, the dedication to democracy among the mixed bag of disenchanted former Sandinistas and equally disgruntled former followers of the Somoza dictatorship whom the president would have us think of, uniformly, as "freedom fighters."

In his radio address, the president didn't even make the case against the Sandinistas as an active menace to their neighbors. He warned only of a "Fortress Nicaragua" that "intends" to export communism. Otherwise he spoke only of what the Sandinistas are doing internally, saying it is "totalitarianism. It is brutal, cruel."

So it may be. Congress isn't haggling about that. But you will hear plenty of argument in Congress over whether "it's totally consistent with our history," past or recent, to support the overthrow by force of regimes whose internal practices we abhor.

True, Reagan still refuses to say flat out that the goal of U.S. policy is to remove the Sandinista government. Instead, he talks about removing it "in the sense of its present structure, in which it is a communist, totalitarian state. . . ."

Leaving aside the semantic nonsense of that response, consider his reply when he was asked, a third time around, whether he wasn't "advocating the overthrow of the present government." His answer was: "Not if the present government would . . . say uncle." If the Sandinistas would let the contras back into the government, he was saying, then they could all get on with the original democratic aims of the revolution against Somoza.

The absurdity of that proposition conveys the hypocrisy, as well as the absence of a serious policy. The problem is not, as Reagan suggests, that Congress doesn't understand what "we're trying to do." It understands all too well. The problem comes down to politics. A president with a special gift for converting pipe dreams into popular causes may not need a serious policy.