Former president Gerald R. Ford led a two-fisted assault on the "weak and wavering leadership" of President Carter as Republicans opened their 32nd convention tonight in a burst of oratory and patriotic pageantry.

Ronald Reagan, who will claim the GOP nomination on Wednesday, flew here today from his California home and told a jubilant welcoming crowd that he and his party "are determined, all of us, to make America great again."

But Reagan was momentarily upstaged as Ford and two of his former Cabinet members indicted the Carter administration as a "mistaken, troubled, dangerous and embarrassing" government, which has brought the economy "to the edge of crisis" and jeopardized international security.

Ford, who beat back Reagan's challenge at the 1976 convention and toyed with the idea of contesting him again this year, referred to the new party standard-bearer by name only three times in his speech.

But he vowed to do everything in his power "to elect our nominee," and said no one will "try harder, work longer and speak with more conviction" in the coming campaign than he will.

If there was any doubt that Ford's motivation is to settle a political score with the man who ousted him from the White House, it was dispelled in the opening paragraphs of his speech.

Recalling that in 1976 Carter said "the president [Ford] should be removed from office" because the "misery index" -- the sum of the inflation and unemployment rates -- "was so high," Ford said:

"Just two months ago, it was 24 percent -- twice as high. That's twice as many reasons Jimmy Carter has got to go."

Ford had a one-word description of what he called "Carter's alibis" for serious unemployment, inflation and overseas crises -- "baloney."

Carter "asks the American people to be satisfied with good intentions. He says the job is too big for any one person. He has given up on the presidency. And still he wants the job," Ford said.

"Well, I know something about the job. I've been there. To give up on the presidency is to give up on America. If Jimmy Carter doesn't feel up to the job, he shouldn't be in it."

Under the master script for the convention, tonight was "indictment night -- with Ford's critcisms of his successor amplified by his administration's defense and treasury chiefs, and by the first two of the vice presidential hopefuls who will parade before the cameras while Reagan weighs their merits.

Ford took responsibility for seeing that the fate of the American hostages in Iran was put squarely into the middle of the presidential campaign.

"Last Nov. 4," he said, "more than 50 among us were taken hostage in Iran.

This Nov. 4, with their tragedy burning in our conscience, we will vote to elect a new American president."

Ford also added his voice to those critical of Carter's decision to curb grain sales to the Soviet Union and cancel American participation in the Moscow Olympics in response to the Soviet invasion of Afghanistan.

"They [administration officials] tell America's farmers they must give up all trade with the Soviet Union -- and the Olympic team must give up their golden dreams," Ford said.

"How must better it would have been to have had the intelligence and foresight to maintain our military strength to deter our adversaries before Afghanistan rather than to penalize our own people after Afghanistan."

Delegates and spectators in Joe Louis Arena, who had managed to ignore most of the earlier oratory, erupted in the first real demonstration of the convention when Ford and his wife, Betty, made their appearance on the rostrum. Every oratorical shot Ford fired at Carter brought cheers.

And when he finished his speech, the delegates sang "Happy Birthday" to the former president, who turned 67 today.

Ford's assault on Carter's record was harsh by the usually polite rules of the White House fraternity. But the language was mild compared to that used by former secretary of defense Donald H. Rumsfeld, a dark horse hopeful for Reagan's runningmate.

"The presidency of Jimmy Carter has been one enormous mistake," he said. "It must end because it is risking our future."

Calling Carter "perhaps the most naive president in modern times" and his administration "a dangerous and embarrassing episode in our history," Rumsfeld said: "You have heard of the proposals to change a president's term to six years. The best argument I know against the six-year term is sitting in the White House today."

Charging that the president had "canceled the B1 bomber, delayed the MX missile, cut the shipbuilding program and refused adequate pay to the men and women of our armed services, "Rumsfeld said: "The things we need to keep the peace have been unilaterally scuttled, and nothing -- not one solid concession -- was achieved in exchange."

While the Carter administration contends it has reversed a decline in defense spending under Ford, Rumsfeld said it had "cut $38 billion from the last Republican defense program," with the result that the Soviets "are spending $50 billion more each year than the United States for ships, guns, tanks and planes."

Rumsfeld borrowed -- without direct acknowledgment -- one of the favorite refrains Sen. Edward M. Kennedy (D-Mass.) used in his campaign against Carter: the characterization of the government as "the surprised administration."

As Kennedy did frequently in the primaries, Rumsfeld said that Carter was "surprised when the Russians invaded Afghanistan . . . surprised that the Russians lied to us . . . surprised the first time our embassy in Iran was seized and surprised the second time it happened."

"President Carter was even surprised to discover how his own ambassador voted on Israel in the U.N.," he said. "We should not be surprised that the world wonders what he will do next."

While Rumfield, currently president of Searle & Co., a Chicago-area pharmaceutical firm, dwelled on the defense issue in his "audition speech" for Reagan's No. 2 spot, another aspirant, Sen. Richard Lugar of Indiana, praised Reagan's approach to economic issues.

"Thank goodness for an election year in this country," he told the largely ceremonial midday opening session. "We will soon have in Ronald Reagan a president who is prepared to kick out the blocks and let the productive wheels of this great economy roll, once more."

The criticism of the administration's economic record was amplified a few hours later when former secretary of thetreasury William E. Simon said Carter had brought "our economy -- once the wonder of mankind -- to a deplorable state." Charging that Carter had raised taxes, federal spending and the national debt to record heights, Simon said the president "has the Midas touch in reverse: everything he touches turns to mush."

"Four years ago," he said, "Jimmy Carter asked all of us: Why not the best? I ask you tonight: Why in heaven's name should anyone now vote for four more years of the worst?"

In the welcoming address to the convention, Michigan Gov. William G. Milliken contrasted "the shiny glass towers" in the Renaissance Center complex, where the delegates converged, with "the broken glass of abandoned storefronts" in the core of the city, hard hit by the auto industry slump.

He reminded them that the covention was being watched by "the poor, the jobless, and so many others who live here -- and all over America -- without hope.

"Let them see from this convention a commitment to the cities, and compassion for those who dwell within them," Milliken said.

Detroit Mayor Coleman Young, a Democrat who has worked closely with Republican Milliken on urban-aid projects, told the delegates: "I hope your party is wise enough to follow the lead of our great governor."

Young was well-received by the Republicans, even when he pointedly noted that his party would be meeting in New York next month to present its proposals for urban needs. "May the best party and may the best program prevail," Young said.

While the city's black mayor was looking out on a largely white audience, program planners went out of their way to show that blacks were part of their process.

The opening invocation was given by teh Rev. Jerry Moore, a Washington, D.C., city council member, and the first motion of the day -- to dispense with the reading of the convention call -- came from another black, Arther Fletcher, defeated GOP candidate in the last D.C. mayoral race.

The woman's touch in oratory was supplied by Sen. Nancy Landon Kassebaum of Kansas, the convention's temporary chairman.

Kassebaum, a supporter of the Equal Rights Amendment, did not refer to the refusal of this year's platform committee to repeat previous endorsements of ratification. But she said that Republicans "seek a nation which never wavers in its commitment to equal rights, equal opportunities and equal justice."

As the convention was getting under way, the rules committee rejected proposals to change the delegate distribution at future conventions and to give more votes to Puerto Rico.

Current party rules include a complex formula for delegate allocation that puts many of the southern and western states at a disadvantage. For example, Michigan, with a population of 9.2 million, currently has 82 delegates, while Texas, with a population of 13.4 million, has 80.

The Michigan delegation suggested a new formula that would have given Texas 130 delegates and Michigan 105 in a convention that would be about 50 percent larger than this one.

The proposal was designed "to encourage and increase participation in the Republican Party," according to John Field Reichardt, the delegate who introduced it. Reichardt argued that the current system discourages Republican organizations in the fast-growing Sun Belt, where the party should have good prospects, by giving these states fewer delegates than they should have.

But the idea was overwhelmingly rejected.

The proposal to give Puerto Rico more than the 14 delegates it has was pressed by some members of the committee as a way of signaling to Hispanic-Americans that the GOP wants and deserves their support.

But the dominant mood on the committee was not to make any voluntary change just to woo some minority votes. "Let's do it by hard work, not by giving delegates away," said David Smith of Georgia, to applause. The proposal was easily defeated by voice vote. The delegates from Puerto Rico asked for a roll-call tally, but was denied.

The rules committee also established a new study panel to examine proposed changes in the system of presidential primaries, after hearing suggestions from Kansas Sen. Bob Dole and others that the system cries out for reform.

Under the proposal approved here, the Republican National Committee will have to take a position on the need for reforming the primary system.

The party's platform committee yesterday formally reported the platform it adopted last week. No minority reports were submitted, apparently eliminating any chance of a floor fight on the platform. However, Sen. Charles H. Percy (R-Ill.) said he was hoping to delete the plank that says a Republican administration will favor appointees to the federal judiciary who "respect traditional family values and the sanctity of innocent human life."