Walter F. Mondale borrowed John F. Kennedy's tactics and rhetoric tonight in a televised debate he hoped would put him back in the race for the White House.

He did his part as well as his managers could have hoped. But Ronald Reagan refused to play Richard M. Nixon -- or even to utter Nixon's name -- and he may have blunted Mondale's strategy by being relentlessly himself.

Mondale clearly had the first 1960 Kennedy-Nixon debate in mind as he faced President Reagan here. He invoked Kennedy's name early, reminding the audience -- including millions of nominal Democrats who, polls say, prefer Reagan -- that the president had been active in "Democrats for Nixon" in 1960, while he had worked for Kennedy in Minnesota.

And Mondale closed the debate by borrowing Kennedy's line that, however good America is today, "I think it can be better."

As Kennedy did when he shared the stage with Nixon, Mondale managed to sound and look sharper than his older, better-known and more credentiated opponent.

Reagan learned tonight what other presidents have learned from their debating experiences -- that any record provides an opponent material for criticism.

Instead of the high-toned patriotic rhetoric that has dominated his front-running campaign, Reagan was forced onto the defensive for much of the 90-minute debate, rebutting charges from Mondale and pointed questions from the three journalists on the panel about his domestic policy decision.

But unlike Nixon -- who disintegrated into a perspiring ill-at-ease and harried politician under the pressure of that first debate with Kennedy in 1960 -- Reagan remained in command of himself and the situation throughout the evening.

He avoided any obvious blunders of that kind that damaged Presidents Gerald R. Ford and Jimmy Carter, when they faced their challengers in earlier debates. Reagan's advisers, who had said in advance that they would be very happy with a "no hit, no run, no error" scorecard, said they thought not much would change after tonight. Polls now show Reagan cruising comfortably 15 to 20 points ahead of Mondale.

But Reagan was clearly nettled by Mondale's repeated claims that he and the Republicians have damaged Social Security and Medicare and would jeopardize those programs again if given another term in office.

"Demagoguery," Regan exploded in the one bit of real emotion he allowed himself in a generally low-key performance.

In part because Reagan was less emotive and facile than usual, Modeale achieved one of his major objectives for the night -- holding his own on camera with the man who has been acknowledged as the master of political television.

Throughout the evening, Mondale's face, voice and posture conveyed at least as much strength as Reagan's -- a crucial point for a candidate who has been plagued by a public perception of personal weakness. One Mondale aid said the Democratic candidate "took command of the debate from the beginning," adding that Reagan went through the debate "without a memorable moment."

Mondale even managed the tricky assignment of being aggressive on issues, without personally attacking Reagan. Indeed, he professed his own liking for the president, although he used Vice President Bush as a punching bag for his attack on the alleged "unfairness" of Reagan's tax cuts.

The biggest gamble for Mondale was his focus on the issue of federal deficits. It was the first topic raised, and Mondale repeatedly brought the issue back to the fore.

His purpose, Mondale told viewers, was to demonstrate that on this "test of leadership," he was offering a realistic program, while Reagan was saying that "it will disappear by magic."

Reagan was defensive on his answers, reiterating his belief that economic growth would assure that sometime "those two lines [of receipts and expenditures] will meet," and ridiculing those who challenged that view.

Mondale won on debating points. But every poll taken so far this year was shown that he is not winning votes on the deficit issue -- even among those who agree it is a serious problem.

Confounding the Democrats' hopes, some people say they think Reagan, not Mondale, will do a better job of controlling government spending and deficits.

Mondale's harping on the deficit issue tonight allowed Reagan to make the charge to a vase audience that Mondale is an inveterate tax-raiser, and to protray himself as a man who will remain a tax-cutter for as long as possible.

Almost as strongly as Mondale played on the fears of elderly Social Security recipients, Reagan appealed to the resentments of young wage-earners toward the rising Social Security taxes that he laid squarely at the door of "the Carter-Mondale administration."

The other issues that moved across the screen gave both men opportunities to play to their core constituencies -- but probably not to shieft many votes.

Reagan reinforced his conservative supporteres by speaking emotionally of his concern for unborn children and for the cause of school prayer.

Mondale reinforced his liberal credentials on those issues by an equally emotional defense of individual rights and the tradition of church-state separation.

On any issue that simply reinforces present lines of division, the outcome has to be presumed to favor Reagan. What the Mondale camp was hoping tonight was that by "taking command" of the cameras and the television screens, their candidate had earned a new audience for his arugments in the final four weeks of the campaign.

The scene that they hoped people would fix in their minds was Mondale turning to Reagan in the closing portion of the debate, and reminding the president that when he uttered his famous 1980 remonstrance to Carter, "There you go again," he was in the process of denying any intention to cut Medicare benefits.

And then, looking Reagan in the eye, Mondale said that the next year, "you tried to cut it $20 billion."

Whatever people judge on the accuracy of the statement, the Mondale camp said tonight that at that moment, as least, Mondale was "standing up" to Reagan.

Some Reagan aids conceded that their champion was perturbed enought by that charge that he wallowed in a statistical morass in most of his following answers, and gave a closing statement as unfocused and unmoving as any of them could remember coming from him in any forum of this importance.

Mondale, on the other hand, was back in his Kennedy mode at the end, arguing that America needs "new leadership" that would "challenge" the nation, rather than waste its energy in "self-congratulation."

That kind of rhetoric worked for Kennedy in 1960. But he was barely trailing in the race when he had his first debate. And his opponent was Nixon, not Reagan.

The chance of history repeating itself did not Reaganites too much sleep tonight. But for the battered Mondale campaign, it may have been a reawakening.