Of all the commentary on the 50th election of an American president, perhaps the most thoughtful came from the loser.

In his final news conference on the morning after his defeat -- and the valedictory to his political career as well -- Walter F. Mondale raised questions about the way we elect our presidents that ought to concern every American. His theme was the dominance of television over the presidential-election process and how it is certain to become a more powerful factor in the future.

"The thing that scares me," he said, " . . . is that American politics is losing its substance. It is losing the debate on merit. It's losing the depth that tough problems require to be discussed, and more and more it is that 20-second TV network news snippet; you know, the angle, the stick, whatever it is.

"I hope we don't lose in America this demand that those of us who want serious office must be serious people of substance and depth and must be prepared to not just to handle the 10-second gimmick that deals, say, with little things like war and peace, but what are you going to do in Lebanon, in Central America, in Nicaragua, in China, in Afghanistan, in Poland . . . . We've got to find people who can handle it at both levels."

Mondale was not offering sour grapes. Nor was he in any way trying to blame the media for his own failures or specifically accuse television for being the agent of his great defeat. President Reagan was not reelected so overwhelmingly merely because he's a master of TV, though certainly his TV skills and TV strategies helped.

As Mondale correctly said:

"Modern politics requires television. I think you know I've never really warmed up to television, and in fairness to television, it's never really warmed up to me . . . . I don't believe it's possible any more to run for president without the capacity to build confidence and communications every night."

The problem is how presidential candidates cut through the snippets of network news footage that form the basic daily portrait of the campaign. The problem is how they deliver a serious message about serious issues.

For now, form dictates superficiality over substance. It puts a premium on the slick good show -- balloons and bands and bigger bands and more balloons -- and an effective performer adept at issuing sonorous generalities and striking attractive poses.

No less a great TV news professional than Walter Cronkite suggests the need -- mandated by law, if necessary -- for a series of lengthy televised debates between the presidential candidates in the fall election periods. That would be one way of ensuring the public has an opportunity to judge the candidates whole rather than seeing them through the barrage of balloons and fragments of video footage that make the most prime time news. That is, the news film cuts in which the candidate makes the strongest attack or worst stumble of that day's campaign.

In the absence of a better way to enable citizens to learn more about the candidates, we're destined to get more of the kinds of campaigns we've just witnessed. And this one has set the all-time standard for most effective use of frothy stragtegy. This one was the classic in how to win through the eye of the camera.

Newsweek's special election issue details just how cynical a process that can be. It describes the way Reagan White House operatives devised their campaign strategy:

" . . . The heart of the matter was to make a vote for Mondale seem almost unpatriotic. Issues had little to do with the strategic design and were in fact seen as a danger if Mondale was allowed to frame them, as he had successfully against [Colo. Sen. Gary] Hart; neither would it be enough for Reagan to stand on what one high-level strategy memo called his 'substantive record of aging victories.' It was instead the conscious intent of his managers to run him as a kind of national icon, seeking reelection less on the particulars of his record than on the atmospherics of that second Era of Good Feeling he had helped bring to life. 'Paint Mondale as . . . soft in his defense of freedom, patriotic values, American interests,' presidential adviser Richard Darman wrote in June. ' . . . Paint RR as the personificiation of all that is right with, or heroized by, America. Leave Mondale in a position where an attack on America's idealized image of itself -- where a vote against Reagan is, in some subliminal sense, a vote against a mythic 'AMERICA.' "

That larger than life Ronald Reagan, the mythical Paul Bunyan of present-day politics, is the one that Americans saw in the fall of 1984.

TV and image-making strategists are not the only problems with the way our presidential campaigns are waged. Two others were at work this year. Both are familiar, both posed even more difficulties in 1984.

The first involved the endless series of primaries, the second the old question about horse-race reporting of the campaign.

If 1984 teaches no other lesson, it ought to be that the primary process must be shortened further. Whether five regional primaries are the answer or not, there's got to be a better way for the public and the candidates. The long process this year worked against the Democratic front-runner, Mondale. He bore the scars that his rivals inevitably inflicted, while Reagan, with no opposition, was home free.

Next time, with the race wide open in both parties, the winning Republican nominee is likely to emerge as crippled as Mondale was this year. It's in the interests of both parties -- and the country -- to shorten the process, cut down on the time and money spent, and to sharpen the real campaign the public sees in the fall.

Then there's our old friend, Dr. Horse Race. Try though we in the media did to rein in our "who's ahead" reportorial instincts, they triumphed as always in the end.

What hope for changes the next time? Not good, if this last Election Day was any indication.

On Election Day, as voters were preparing to go to the polls around the nation, readers of this paper were given a preview of the campaign to come. There, in the main news section, covering half a page, was an article headed: Hopefuls Hit the Road -- for '88 Presidential Race Seen Wide Open in Both Major Parties

So much for a temporary respite from the horse race. Buckety-buck, away we go, galloping off again.