President Reagan appeared initially to have failed last night in his aim to create bipartisan support in Congress for his disputed policies on Central America. While Republicans cheered his forceful description of Soviet and Cuban threats to stability in the region, Democrats faulted the administration's reliance on military and covert responses.

"Instead of trying to do something about the factors which breed revolution, this administration has turned to massive military buildups at the cost of hundreds of millions of dollars," said Sen. Christopher J. Dodd (D-Conn.), who delivered the official Democratic response to the speech.

Dodd characterized Reagan's policy in Central America as "ever-increasing military assistance, endless military training, even hiring our own paramilitary guerrillas . . . . This is a formula for failure."

Meanwhile, Sen. John G. Tower (R-Tex.) said: "The president made a compelling case of our need to come to terms with the critical situation in Central America. Our own security interest is clearly threatened by communist expansion in the region."

The common thread running through most reaction to the president's speech to a joint session of Congress was that most members agreed with, and enthusiastically applauded in several instances, Reagan's description of Soviet and Cuban attempts to win new allies and potential bases in the Caribbean and on the Central American isthmus, which separates strategic waters in this hemisphere.

But still-numerous critical members said Reagan's unabated demands for higher levels of military aid and his failure to address covert CIA operations in the region may cost him support for his policies.

"We are fully prepared to defend our security and the security of the Americas, if necessary by military means . . . ," Dodd said. "But many of us in Congress--Democrats and Republicans alike--disagree with the president because we believe the means he has chosen will not fulfill them."

"They the administration have so rejected any effort for a bipartisan consensus in Central America that the president may be beyond the 11th hour for seeking one," said Sen. Patrick J. Leahy (D-Vt.).

A number of congressmen and Latin American experts said the sometimes combative tones of the president's speech offered little to members who were hoping that Reagan would strike a new chord in attempting to engender successful negotiations in the region.

Reagan called Nicaragua a "tyranny," and asked, "Must we sit by while independent nations of this hemisphere are integrated into the most aggressive empire the modern world has ever seen?"

"He kind of brought the Cold War to Latin America," said Robert Leiken, senior Latin American fellow at the Georgetown Center for Strategic and International Studies.

"It sounds to me like the same old song," said Wayne Smith, former chief of the U.S. interest section in Cuba who quit last summer in protest over U.S. policy toward Latin America. "I see nothing in this speeech that we are going to in fact explore energetically the possibility for a negotiated solution in Central America."

Senior officials who briefed reporters before the speech said it was intended to tell Congress that it will have to take responsibility for any setback in Central America if it does not give the president the support he is seeking.

"The president's tone was just right," said Sen. Robert J. Dole (R-Kan.). "His speech gave a clear statement of our responsibilities."

Dodd said Reagan could not blame Congress if "things were not going well in Central America. We have given him what he asked," he added, in reference to $700 million in economic and military aid appropriated for Central America since Reagan took office.

"One of every five Salvadoran soldiers fighting for its government was trained right here in the United States," Dodd continued. "Now the president asks for an even greater commitment . . . . American dollars alone cannot buy military victory."

Rep. C.W. (Bill) Young (R-Fla.), one of six Republican members of the House Intelligence Committee who are seeking to forestall a vote to cut off covert CIA operations in Central America by asking House leaders for a secret session on the subject, agreed with Dole. "I think the president gave an effective and accurate description of the threatening situation in the region," Young said.

Reagan did not specifically mention covert support for several thousand opponents of the leftist Sandinista government of Nicaragua who are mounting a guerrilla campaign from bases along the Honduran border. He reiterated that it is not U.S. policy to overthrow the Nicaraguan government, but he said that "we should, through diplomacy, offer an alternative."

The House intelligence oversight panel is scheduled to vote today on legislation to cut off funding for the CIA program and replace it with an overt effort of conventional surveillance and other means to stop arms flows without striking at targets inside Nicaragua.

Reagan characterized as "propaganda" reports that CIA-backed forces are drawn largely from the ranks of national guardsmen from the regime of Nicaraguan Gen. Anastasio Somoza, who was overthrown in July, 1979.

Reporters who have been allowed to travel on secret patrols with these U.S.-backed forces reported that many of their field commanders were former guardsman, though their leadership is more broadly based and includes many disenchanted Sandinistas.

In what may have been an indirect reference to those guerrillas, now operating inside Nicaragua with some popular support, Reagan said: "We should not--and we will not--protect the Nicaraguan government from the anger of its own people."

Nicaragua's deputy foreign minister, Victor Hugo Tinoco, said he interpreted the president's remarks to mean that the United States "is going to continue to aid the counterrevolutionaries."

"President Reagan tried to promote the idea that it is necessary to continue with the military line; my personal opinion is that this line ties the United States more and more deeply each day to the military in the region. If this line continues, it will inflame the conflcts in all of Central America."

Two House Foreign Affairs subcommittee chairmen, Dante B. Fascell (D-Fla.) and Michael D. Barnes (D-Md.), said they thought Reagan had failed to forge bipartisan support for his Central American plan.

"I think quite frankly that the president missed an opportunity tonight," said Barnes. "I regret that the president of the United States would give a major address of this kind and not put significant focus . . . on social, economic and polticial problems that are the base of the problem in Central America."

One House Republican who has consistently differed with Reagan on Central America, Rep. Jim Leach of Iowa, said that the president had correctly described the communist threat in the region, "but his prescription for the problem is deeply wrong" because it does not address the "human dimension."

Meanwhile, Rep. Jack Kemp (R-N.Y.) pleaded with his colleagues to support the president and not "let the flame go out" in the democracies of Central America.

Rep. Wyche Fowler Jr. (D-Ga.), chairman of the intelligence oversight subcommittee in the House, urged Reagan to drop his opposition to direct negotiations with the Nicaraguans and "to break out of his preconceived ideological straitjacket to take a fresh pragmatic look" at the region so he can develop "a national consensus of policy for Central America."