In my disgracefully checkered past I was, briefly, a professor of political science. The profession was, and doubtless still is, infested with persons who were happy only when counting things. Some persons practiced "content analysis," whereby they would read, say, the works of Lenin and count the number of times and the spirit in which he used the word "imperialism." Then they would come to the thunderous conclusion that Lenin talked a lot about imperialism and did not approve of it.

Applying that scalpel of scholarship to Walter Mondale's debate performance reveals -- are you sitting down? -- that he likes strength and knowledge. Subtract the questioners' time from the 90 minutes, and divide by two: Mondale probably spoke for 40 minutes. Into those minutes he crammed at least (I may have missed some) 39 uses of the words "strength" and "strong" and 21 uses of the words "knowledge" and "know."

Early on he said: "Strength requires knowledge." In his closing statement he referred to strength and knowledge 14 times. He understands this about communicating to the masses: Keep the message simple ("Coke is it!") and repeat it relentlessly.

But the remarkable discipline he brought to the debate was not sufficient to solve his problem. He reached age 56 and the October of his longed-for campaign with problems that were too numerous and too intractable to solve.

Ronald Reagan went to Kansas City -- the scene of his heartbreaking but toughening near miss at the Republican convention eight years earlier -- with the support of more than one-fifth of registered Democrats. These include a high proportion of conservative, blue-collar Democrats who helped elect him. Mondale had to try to pry a lot of them loose by convincing them that he is personally strong, that he understands national strength, and that Reagan lacks the knowledge to make his instincts and values safe and effective. But Mondale's checkered past caught up with him -- mildly, because Reagan referred only briefly to Mondale's Senate record.

When I quit being a professor I worked on the Senate staff, where I watched Mondale and kindred spirits having fun -- and it was jolly fun for them -- voting against the military systems that today are the sinews of America's strength. The Mondale who was senator from Minnesota was the Mondale who reportedly resisted Jimmy Carter's conversion when Soviet behavior convinced Carter of the need for rearmament.

And that was the Mondale on display from January through June this year, competing with Gary Hart to see who could seem most indiscriminately ardent for arms-control agreements and most reluctant to comtemplate the use of force. As Mondale says, he has a long record in public life. It is too long to erase, even with 39 incantations of the words "strong" and "strength."

Reagan made a hash of some answers and statements in this year's debates, but he botched nothing as badly (and nothing as important) as Mondale did when asked by two questioners to explain what would be frozen and how verification would work under the "mutual and verifiable freeze" that is the centerpiece of his campaign. He implied that "we have an arms race under way" because Reagan is president, an interpretation of postwar history too perverse to merit confutation.

In Kansas City, yet again, he said, in effect, "we have a runaway arms race" because Reagan will not agree with the Russians. Mondale could have said "strength" 1,000,039 times and his clear message still would have been the one identified by Jeane Kirkpatrick in Dallas, in the best speech of this campaign: Democrats always blame America first.

Reagan, for his part, said "we seek no (military) superiority," thereby repudiating, again, an important part of his 1980 platform. And he said of the Soviets, "We're not going to change their system." This recurring theme of his administration (last week Secretary of State Shultz said, "We mean no threat to the security of the Soviet Union") raises this question: Why are we participating in the "Helsinki process, " given that compliance with the Helsinki agreements on human rights would require fundamental change in the Soviet system, and would mean fundamental insecurity for the Soviet elite?

And if Reagan means what he recently has said about restoring "full independence" to Eastern European nations, his aim is incompatible with what the Kremlin considers its essential security interests. Someday someone should ask him about this.