IT'S BEEN SIX WEEKS since the election and I have yet to see mention made of what I regard as the major factor in Jimmy Carter's defeat. He had begun to bore his fellow Americans. And boredom, in a land of media titillation so intense that attention spans can often be measured in seconds and almost never exceed 60 minutes, is one thing that will not be tolerated. In the last 12 years we've had four presidents and we'll add a fifth next month. Switch the channel, change the show. Enough of Jimmy and Rosalynn and Miss Lillian and Brother Bill. They seemed engaging four years ago, but now they belong with Tricia and Lynda Bird and Betty Ford. It's time for Ron and Nancy.

Of course, channel-switching wasn't the whole story. Ideology had something to do with it. But just as much as it was pro-conservative, it was anti-liberal, and I think most expecially anti-conventional-liberal. Look at the Democratic senators who bit the dust. Mostly good men, but mostly unoriginal men. Their liberalism was the kind that has become inshrined in alliances like the one between the Democratic Party and Big Labor. I think the people had begun to resent, for example, the fact that these senators would seldom consider an idea opposed by Big Labor. Common sense suggests that there are bound to be times when the humane objectives of liberalism could best be achieved by ideas that the unions oppose.

Take the problem of teen-age underemployment, which is, as we all know, particularly acute among already disadvantaged blacks. Liberals should be determined to try any idea that has a reasonable chance of actually doing something about a problem that has been so frustratingly intractable. So, even though Big Labor opposes it, why not try a lower minimum wage for teenagers only, as an incentive to get employers to take a chance on them. Or do you think no incentive is needed? If so, remember how, when you were a teenager and were supposed to mow the lawn, you managed to oversleep until you were reprieved by rain, dinner or some other excuse? Perhaps you weren't like that, but I certainly was, and so were many of my friends. It is simply unfair to expect an employer to offer such teenagers the same wages he would pay mature adults.

Everyday brings something new to worry about. The latest example, from a recent op-ed piece in this paper: "For too long we have not cared about the child whose parents are affluent."

Another example comes from an appeal for aid for Grenadan Children issued by the Grenada mission to the Organization of American States. Gone were the old stories about grinding poverty, malnutrition and disease. Instead, the Grenadan officials painted this bleak picture:

"In 1979 there were nearly 15,000 children in Grenada under the age of 5. At the same time there were only 11 child-care centers. This means the vast majority of the nation's preschool children were being cared for at home, some by mothers forced to stay home and thereby abandoning employment opportunities. Others received care from loving but untrained grandparents."

Being cared for at home! By mothers! Or by untrained grandparents! Well, it does beat being affluent.

More heartening news from our public schools. A task force report criticized the Prince George's County school system for hiring teachers on the basis of their education credentials instead of their competence, complaining that the county administers only a "one-hour test in spelling, grammar and mathematics for prospective new teachers." But the system was able to reply that Prince George's is the only county in Maryland and one of the few in the nation that requires any test at all.

Recent research by scholars from Purdue, Colorado State and the universities of Wisconsin and Manitoba indicates that violent pornography inspires violence. Like the findings of most research in behavioral science, this strikes me as just about as surprising as the news that hungry men want to eat. Still, it reinforces my belief that we ought to keep the "entertainment" of violent pornography off TV.

This kink of censorship does not bother me in the least, and I am astonished by the legal minds who cannot distinguish between it and the censorship of political discussion, which should never occur.

I am similarly astounded by the aptitude for making distinctions displayed by the federal prosecutors who chose to indict two FBI officials who were slightly naughty in their pursuit of the violent Weathermen, while doing nothing to punish the officials who carried out Cointelpro, the vicious FBI plot to harass nonviolent dissidents.

The American legal system's failure to distinguish violent and nonviolent crime is a triumph of the liberal mind at its very worst. In most jurisdictions the man who picks your pocket is no less likely to go to jail -- or to get off scot-free -- than the man who assults you. Need another example? A Maryland judge, after hearing four women tell of being tortured by a rapist, gave the guilty man the kind of a sentence that I believe in -- one that would have protected society from his favors for many years, until he was well past the point of wanting to rape anyone. But the judge then decreed that before going to prision, the rapist be referred to a mental hospital for "psychiatric evaluation." There the psychiatrist will have the power to commit him -- or release him at any time.

The attonrey for Bernard C. Welch, the man accused of killing Dr. Michael Halberstam, has already been granted a psychiatric examination for his client and will no doubt succeed in pleading insanity somewhere along the long road this case will travel as it wends it way through trial and appeal. He will succeed because all violent criminals are insane. He should not succeed because, while their insanity should excuse them in the eyes of their Maker, it certainly should not prevent us from protecting ourselves by locking them up for a long time.

My neighborhood -- Adams-Morgan -- may have the nation's most elegant graffiti. My favorite, scrawled in spray paint on the wall of a nearby bank, is "Paul Volcker Sux." Evidence to support this allegation comes from The Wall Street Journal, which in a recent issue reported, "More than 5,500 companies, mostly small, have failed in this recession" -- a recession in large part caused by Volcker's high interest rates. The effect of those small business failures on employment is suggested by an MIT study on "The Job Generation Process," which found that during the period 1969-1976, small firms with 70 or fewer employes generated 66 percent of all new jobs in the United States.

Pat Caddell, the Carter pollster, has explained that Carter's strategy in his debate with Reagan was aimed at specific constituencies in the television audience. It was this focus on constituencies -- blacks, women, you could almost see Carter ticking them off in his mind -- that I thought was the worst thing he did in the debate. And it is the worst thing about Democrats today. They practice the politics of selfishness, appealing to various groups in ways of emphasize self-interest. I don't think the Democrats will win again until they stop appealing to selfishness and once again reach out to the best that is, and always has been, in our people. Remember that when Woodrow Wilson was criticized for being an idealist, he replied, "That's how I know I am an American."