ON THE RADIO, a commentator is talking about the oil crisis. What he says goes in one ear and out the other - something about how things would be different if President Carter had stuck with the shah. The commentator starts winding up. You can tell the end if coming.

"At least that's the view from here," he says. "This is John Ehrlichman." And this is Richard Cohen driving. I almost went right off the road.

When I got to the office, I called the station. I was not sure I got the name right. The one I heard belonged to former President Nixon's chief domestic aide, who had served 15 months in jail for his role in what is called The Watergate Conspiracy and also for his role in the burglary of the offices of Daniel Ellsberg's psychiatrist.

It turned out it was the same man, and it turned out moreover that he does these commentaries five days a week. It also turned out that I was the first person to call and ask, more or less, if it was germane that he once served time in the clink, that he is, in the jargon of the day, and adjudicated felon, a criminal - the sort of man who would conspire to rummage throuh someone's psychiatric file, not so he could offer some suggested treatments, mind you, but to destroy the man politically. Do we want to know what this man thinks about anything?

I don't know. It's hard to say any more what the rules are. In Maryland one night, the former speaker of the state's House returned to one of the legislative watering holes not too long after serving a jail term for political corruption and he was greeted like a hero.

No one avoided him. No one walked by his table and spit on the tablecloth. No one pointed a finger and said "shame on you." Instead, they bought him beers and laughed at his jokes.

There are other examples of this sort of thing. In Washington, you are constantly running into people who either barely escaped jail or did a stretch, and you have to watch with wonder as they go on with their bussiness. In Los Angeles, David Begelman, the former head of Columbia Pictures, didn't even lose his favorite table at Ma Maison, the Sans Souci of the movie colony, after admitting he stole from the corporate kitty.

What he did was make out checks to actors like Cliff Robertson, cash them himself, and let Robertson, who was not supposed to notice, pay the taxes. All the time, Begelman brazened it out as if a guilty plea or two is par for the course - a business matter, like bankruptcy.

Begelman, in fact, is something of a one-man, modern-day morality play, replacing Spiro Agnew as someone who incorporates many of the moral and ethicaal contradictions of our times. In some ways, he has gone Agnew one better. The former vice president merely said he was framed and then went on with his life. Begelman named his framer - himself. He explained his actions by saying he had this need to fail - an insight surely gained on the psychoanalyst's couch, one that turns himself and not the company he fleeced into the victim.

The point here, though, is not what Begelman has learned or not learned about himself, but rather what he and others like him tell us about ourselves. It is clear, for instance, that we're no longer sure if it is better to be pure or successful, and it's even clearer that we will do anything to avoid a scene.

The age of moral outrage is over and I, for one, am always shaking hands with men I detest - some of them truly evil, most of them personable as can be, and some of them corrupt only in ways that would interest journalists: they have sold out their own craft. What Begelman did was prove he knew his audience. He acted as if he had done nothing wrong, and sooner or later he was treated in exactly that way - as if he had done nothing wrong.

That is the danger with Ehrlichman and the other Watergaters - all of those who, in their own inventive ways, tried to corrupt the political system. No one wants to badger them, to ignore the fact that a person can change for the better. But those charitable instincts sometimes make it appear as if nothing at all had happened - that this jail nonsense was all about nothing or, worse than that, routine - a mere interruption in a stunning career.

This, more or less, is how it is handled in the press release announcing Ehrlichman's debut as a radio commentator. It's just stated as a fact. On Ehrlichman's own resume, it is not even mentioned - as if it never happened.

But somewhere in the back of your mind you know he really did go to jail. In fact, this - this Watergate notoriety - is what makes John Ehrlichman famous today, what gets him on talk shows so that his novels - pretty good novels at that - sell.

It is almost as if jail is no stigma at all, but a bona fide, a credential - proof that you were really there and up to your ears. In this way, John Ehrlichman is not much different than some punk right out of the slammer who is gretted as a hero by the kids on the blocks - bad, maybe, but not half as bad as his admirers.

That's the way it is also with Ehrlichman's radio show. Good or bad, it'll tell us more about our view of the world than it ever will about his.