TO THE PROGRESSIVES in the House, David McCurdy (D-Okla.) is a suspect figure. Last year, he helped President Reagan get $27 million for the contras and assured his colleagues he had the president's promise that he would negotiate with the Sandinista government.

Now, however, the liberals are glumly lining up behind his alternative to the presidential proposal for $100 million in military aid to our mercenaries.

"It's not easy selling McCurdy," says Rep. David Bonior (D-Mich.), who is trying to persuade his liberal brethren that the ambitious Oklahoma Democrat is not in this instance a collaborator.

The realities of the contra vote, which is expected on Tuesday, is that while 200 Democrats stand firm against any aid at all, the magic number of 218 cannot be achieved. In the middle, controlling the outcome, are 25 or 30 Democrats who blanch at the thought of voting for nothing.

They feel so strongly about it that they would, if faced with the choice, vote for $100 million in military aid rather than for nothing, as proposed by Rep. Lee Hamilton (D-Ind.) With the Republicans solidly backing military aid, the president would win a total victory.

House Speaker Thomas P. O'Neill, Jr. is backing Hamilton, but when push comes to shove, he will have to join McCurdy. He is "not twisting arms" in McCurdy's behalf.

Bonior is urging liberal colleagues who wish to vote nothing to reconsider. "Look at the bill, not the personality," he says.

The alternative proposed by McCurdy, who has been cured of his delusion that the president would ever willingly negotiate with his counterpart Daniel Ortega, specifically requires direct talks between the U.S. and Nicaragua. It also provides $75 million in "logistical aid," bans the "lethal" variety and requires the president, after 90 days in which peace, presumably, is given a chance, to come back for release of the money.

Bonior tells the unhappy Democrats that it's about the best they can expect, since they are in the hands of the brokers.

Nobody hopes for anything constructive from Ortega, the president of Nicaragua. The day before the Senate vote, in one of his recurrent fits of bad timing, his troops crossed the Honduran border, as they often have before, in pursuit of contras. Reagan pounced on the crossing and inflated it to an "invasion". Honduran authorities were all off at the beach, but were persuaded, on receipt of $20 million in U.S. emergency aid, that their territorial sovreignty had been violated and that they were in trouble.

The press made much sport of the affair, but not until after Speaker O'Neill had lost his temper with Ortega and called him names. Ortega had seriously aggravated him a year ago by going to Moscow after the speaker had broken a pick to keep the House from voting contra aid. The speaker is in a little trip flap of his own right now, having been attacked by the U.S. ambassador to Argentina for his conduct as leader of a recess excursion to Latin America to find out if leaders in the area were saying the same thing publicly and privately about contra aid.

All this is of passionate concern to Washington, but not to the country, which is standing firm in the face of presidential alarums, 2 to 1, against any meddling in Nicaragua. They don't seem to care where Ortega goes or what he does. They pay no attention when the President and his men cry that the Sandinistas are coming to Harlingen, Tex., or San Diego, Calif. They tune out on lurid tales of drug trade and human rights atrocities. They think the money that is being talked about should be used to bail out farmers. Where Reagan sees another Cuba, they see another Vietnam. They want no part of it.

Members who tremblingly voted against aid on March 20 went home on the Easter recess to thanks and praise from their constituents.

Since they returned, they have received another jolt. The Contadora talks have collapsed -- "torpedoed" by the Sandinistas, says the president.

Bonior says the failure was "foreordained." The latest Contadora proposal asks the Sandinistas to reduce their armed forces before the U.S. withdraws suport for the contras. "They regard that as suicidal," says Bonior. "But the Contadoras wanted the Sandinistas to make the first move, as a gesture of good will."

Good will is in short supply in any corner of the contra aid picture. What is written all over it is the iron will of a president who never says uncle and who has forced Democrats to the point where they don't dare do nothing for the contras.