Democrats and Republicans alike said yesterday that, even though the House voted to kill all further assistance to Nicaraguan insurgents Wednesday night, some form of humanitarian or "nonlethal" aid is likely to be approved if the issue resurfaces as expected later this year.

A proposal backed by President Reagan to give the "contra" rebels nonlethal aid failed by only two votes, 215 to 213, and several moderate and conservative Democrats who voted against it said they would have voted in favor had they known the alternative was going to be no aid at all.

Once the House killed the Reagan-backed proposal it also killed a Democratic alternative it had earlier approved; liberal Democrats decided that their real choice was nothing.

"A number of people would've looked at the Reagan-backed proposal in a different light if they had known what was going to happen on the final vote," said Rep. Dave McCurdy (D-Okla.). "I would have voted for it."

At the White House, presidential spokesman Larry Speakes said yesterday that the administration was looking for ways to force further votes on the issue. "The president will not abandon his goal," Speakes said, and characterized the House voting Wednesday not as defeat but "the beginning of victory."

On Capitol Hill two rebel leaders, Adolfo Calero and Alfonso Robelo, said their war against Nicaragua's leftist Sandinista government will continue.

They said the House outcome was "a communist victory, but the civil war . . . continues" and announced that their offer of a cease-fire and talks with the Sandinistas pointing toward elections remains in effect until June 1.

Lawmakers said yesterday that the Wednesday outcome of no aid bill at all was the result of parliamentary one-upsmanship, not a reflection of the true mood of the House. Many also said the Reagan administration could probably have saved some form of aid had it given earlier and more forceful support to the non-lethal aid plan that so narrowly failed.

"If they administration officials had come in initially with that, it might have passed," said House Majority Leader James C. Wright Jr. (D-Tex.).

"It was not handled well from start to finish," said House Minority Whip Trent Lott (R-Miss.). "More aggressive support, earlier decisions would've made it possible to win."

But there was finger-pointing as well at the Democratic liberals, the Republicans who also voted no en masse at the end and the Democratic leadership.

Both parties are protecting their flanks lest the Nicaraguan vote become an issue in next year's elections.

The House action Wednesday came in three votes. The first was on a Democratic leadership proposal to end all aid to the rebels but provide $14 million for refugees outside of Nicaragua and for implementation of any future peace treaty in the region.

That was approved 219 to 206. A few liberal Democrats, who opposed any form of aid that might reach the rebels, joined Republicans in voting no.

But almost all other Democrats voted in favor, as did some liberal Republicans.

The second vote occurred on the Republican substitute offered by Minority Leader Robert H. Michel (R-Ill.), which was to give $14 million in nonlethal assistance directly to the rebels for food, clothing, medicine and equipment but not weapons.

That fell 215 to 213 as most Democrats, heavily lobbied by their party leadership, voted no.

The last vote was on final passage of the measure. That would have sent it to the Republican-controlled Senate, which earlier in the week voted for $14 million in military aid. It would have preserved a legislative vehicle for working out a possible compromise.

But on this vote, liberals who had supported the Democratic leadership proposal only for defensive reasons -- to make more palatable a bill they basically disliked -- switched sides and voted no. Republicans, meanwhile, feeling that the Democratic measure was an abandonment of the rebels, also voted no. The final vote, which stunned many in the chamber, was 303 to 123 against the bill.

Yesterday, Lott said the outcome of the three votes had produced "a lot of soul-searching and guilty consciences. Several of them feel like they were duped."

He said that "at least half a dozen moderate Democrats" told him they felt they had been taken in by their liberal colleagues, who were quoted after the vote as saying the final result was what they wanted even though it had required a "circuitous" route.

McCurdy, a member of the House Permanent Select Committee on Intelligence, which will soon mark up the administration's 1986 request for $28 million in military aid to the rebels, said, "I think there's a lot of diappointment among Democrats who worked very hard for the Democratic alternative."

He said he has already contacted the White House about trying to work out a compromise to resurrect the program. "I think there's some feeling that we don't want to just leave those people down there hanging," he said.

"It was a great mistake to end up with nothing," said Rep. James R. Jones (D-Okla.), who cosponsored the Democratic alternative. "The closeness of the two alternatives tells me there is still a majority to apply pressure, to use diplomatic and economic methods and then to revisit that" to see if further pressure is needed.

Intelligence Committee Chairman Lee H. Hamilton (D-Ind.), one of the cosponsors of the Democratic alternative, said yesterday that he had hoped something would pass and "was surprised by the extent of the Republican vote against it."

Several Republicans said they thought the GOP leadership had erred in not pressing its members to support the measure to keep the program alive in some form. "The Republican leadership made a profound mistake in not voting for it to pass and then go to conference," said Rep. Jim Leach (R-Iowa), who cosponsored the Democratic alternative and voted against the GOP proposal.

But one member of the GOP leadership, Rep. Dick Cheney (R-Wyo.), said, "For many of us there was a very strong feeling that that bill was so bad that we didn't want our names put to it. We didn't treat it as a serious proposal."

He said the Republicans most strongly objected to an indefinite extension of the provision in current law that bans the direct or indirect use of any U.S. funds for military or paramilitary actions in Nicaragua.

Lott said that once the Michel alternative was defeated the bill was just too watered-down to support. "If it got any weaker than Michel we might as well have sent them [the rebels] a love letter and said goodbye," Lott said.