When the Reagan administration unveiled its program to reform immigration laws, Attorney General William French Smith made it sound almost irresistible.

"The administration program is simple and direct," he said. "It is intended to be fair, humane, something we can afford and a way of reducing the large, fugitive class we now have living within our country. Most important, it should enable us to regain control over our own borders."

Last Saturday, with about 300 amendments awaiting consideration in the House, the immigration reform bill died, a victim of a ticking clock and the interests most affected: employers, labor and minorities.

By that time, the measure had become something for the interests to hate and, as the final hours of the lame-duck session approached, that opposition was overwhelming.

"If that bill, without a change of a word, had been voted on by the House of Representatives, it would have passed by a hundred votes," said Romano L. Mazzoli (D-Ky.), the legislation's chief House sponsor. "There's nothing wrong with the bill. The big problem was lack of time."

But Mazzoli understated opposition to the legislation he had co-sponsored with Sen. Alan K. Simpson (R-Wyo.). Despite the most serious effort at immigration reform in many years, the bill led to opposition from the Hispanic community, organized labor and agricultural growers of the Southwest.

The bill was intended, as Smith had said, to regain control of U.S. borders. Each year approximately 1 million people are apprehended attempting to enter the United States illegally, mostly along the nearly 2,000-mile border with between the United States and Mexico.

For every person apprehended, several others slip secretly into the country. The Census Bureau estimated in 1980 that between 3.5 million and 6 million illegal aliens live in this country. Others cite many more.

In addition, the highly publicized influx of Cubans and Haitians into Florida underscored the need to restitch the country's tattered system of immigration control.

"The United States must never again permit its immigration policy to be set in Havana or any other foreign capital," Smith told a joint House-Senate subcommittee last April.

The Simpson-Mazzoli bill, written with advice from the Reagan administration and a federal immigration task force headed by the Rev. Theodore Hesburgh, president of the University of Notre Dame, contained three major elements.

They were tougher enforcement of existing immigration restrictions, sanctions against employers who knowingly hired undocumented workers and an amnesty program to allow undocumented workers already in the country to become U.S. citizens eventually. Smith called it "rational and comprehensive," and in August the Senate approved it, 80 to 19.

But objections of principal interest groups had not been overcome.

Hispanics, led by the Mexican American Legal Defense and Educational Fund (MALDEF) and the League of United Latin American Citizens (LULAC), argued that the measure would lead to further discrimination against Hispanics who were U.S. citizens or legal aliens, without materially slowing the influx of undocumented workers.

"The Mexicans and Salvadorans and Haitians are coming for a lot of reasons, but the primary reason is survival," LULAC's Arnoldo Torres said. "A new law is not going to stop them."

Growers disliked the sanctions and accompanying regulations and said they feared they would lose workers if they bill were enacted.

"We said from the beginning we did not like sanctions, but if you were going to do it, the least you can do for us . . . is to provide a program so that when . . . the crops are ripe, we could get temporary farm workers," said C.H. Fields, assistant director of national affairs for the American Farm Bureau Federation. "We did not get that assurance."

But the proposal for a "guest worker" program brought strong opposition from organized labor, which said it feared that foreign workers would take jobs from Americans. In addition, labor said it believed that "guest workers" would be used to break strikes.

When the bill reached the House floor, Hispanic organizations had proposed so many amendments that the leadership pulled it from the floor.

Simpson was quoted as saying, "I'm excited about its prospects of passing the next time." But Mazzoli said yesterday, "Like a big brown bear, I'm going into hibernation."