After all, the saying goes, what's a little white lie between friends?

Mike Royko, the irrepressible Chicago columnist, thinks a lie or two or three or maybe a million might save the nation.

In his column yesterday in the Chicago Tribune, Royko pointed out to his readers that he'd never, in 20 years, asked them to give, donate, help or take part "in any other journalistic do-good endeavors."

But now--"this one time," he wrote--he was asking readers to "join me in a noble cause."

Lying.

" . . .a good lie, a worthwhile lie, a lie that will put bounce in your step and a giggle in your voice and make you feel wonderful."

A lie, in fact, to the television network exit pollsters in next week's Illinois primary elections.

"Be polite. Talk to them," urged Royko, but "don't give them one honest answer. If you voted for Mondale, say you voted for Hart. If you voted for Hart, say you voted for Mondale. Or if Glenn is still in the race, say you voted for him.

"When they ask you why you voted for Hart, say it is because he is so mature and serious that he reminds you of your grandfather.

"Or say you voted for Mondale because he reminds you of Johnny Travolta."

Last month, Rep. Timothy E. Wirth (D-Colo.) held hearings on the potential damage to the electoral process being done by network exit polling and its use by the networks to project winners before the polls close. Wirth had been at a polling place in west Denver in 1980 when the the network word came flickering across the Rockies that Jimmy Carter had lost. "Tim actually saw people leaving the lines," an aide said yesterday.

The aide refused to take a position on the prevarication issue, but said that the Wirth communications subcommittee had received more than a thousand letters after the hearing and that there seemed to be a growing support for the rule to keep the TV pollsters and their clipboards at least 300 feet from the polling places.

But Royko believes that the lies have it.

When asked yesterday what finally prompted his column he said, after allowing that he had space to fill, "I really do get fed up with these TV guys. They've taken politics away from both the politicians and the voters. They're more and more boorish in their interviews and you're never sure whether the candidate is the reason they're there or whether they're the reason the candidate is there or the anchorman is the reason either is there.

"Elections used to be fun," Royko mourned. "Watching the returns coming in with the excitement of knowing that a couple of wards or counties or states that were still out might make the difference. But the networks have taken the fun out.

"And I really do think that when the minds of the voters are being so manipulated . . . with this business of momentum . . . why it's TV that declares what the expectations are. If you look, Mondale is leading in delegates and that used to matter. Now they've decided he has to win the popularity contest . . ."

In his column Royko wrote that ". . . if enough of you lie, the entire nation will be treated to one of the finest evenings of television viewing since the tube was unleashed.

"As the evening wears on and the actual votes are counted, we will see Dan become more and more wild-eyed. We'll see Peter hyperventilating. And even David will look like he is fully awake. And they'll all be stammering about how 'goodness, something seems to have gone wrong.' "

Wrote Royko, "Don't doubt that it can be done. I once saw it happen on a smaller scale.

"A few years ago, I was asked to spend an election night at a Chicago TV station talking about the results.

"One hour before the polls closed, a meeting was held and one of the polling gurus came in and announced the result of the state's attorney race.

"He said: 'Bernard Carey has won with 63 percent of the vote. But there is a margin of error, so we are calling it at 57 percent.'

"All the TV newsmen nodded their heads. I said: 'You aren't going to say that on the air, are you?'

" 'Of course,' they said.

"'You're nuts,' I said. 'He not only won't get 63 percent or 57 percent, he might lose.'

"The polling guru looked at me as if I were something that had come out from under a rock. And a TV whizbang said: 'They're never wrong.'

"So before any votes were counted, they went on the air and declared Carey the winner as did another station.

"And I went on the air and declared that they were all nuts.

"By midnight, when the real votes had been counted, the polling guru looked suicidal, the TV whizbangs were sweating through their pancake makeup, and Carey lost with 49 percent of the vote.

" 'How did you know?' a whizbang asked me.

"I explained that because of Chicago's unique political atmosphere, many Chicagoans would not dream of telling a stranger how they voted in an important local election. They have a deep sense of privacy. They also fear a brick through their windows.

"Many Chicagoans had simply lied to a stranger that day.

"Unfortunately, Chicago, like the rest of the nation, has now become accustomed to exit polling. Some people probably believe that they are required to answer."

But, wrote Royko, "It can be done . . . All you have to do is tell a little fib. Then go home, sit back, relax, and watch the anchormen slowly swallow their tongues."