WASHINGTON. — They say Mo Udall is about to resign from the House. If he does, life in Washington will be a lot duller and less amiable than it has been for the past 30 years with him around.
Nobody has been more consistent and outspoken in politics, and made more friends despite it, than the one-eyed, 6-foot-5 congressman from Arizona. For years, he has suffered from Parkinson's disease, yet been able to make jokes about it. He has been in the hospital since he took a serious fall in January.
Mo can make jokes about anything, and even the butt of them usually ends up laughing. Lots of times he himself was the butt. When he was running for president in 1976, he would emulate the Alabama politician who finished his speech in a little town and said, ''Well, ladies and gentlemen, them's my views, and if you don't like 'em, well then, I'll change 'em.''
Trying to recruit workers to his campaign, he recalled the preacher whose notice board outside the church said ''If you're tired of sin, come in.'' Underneath that, Mo said, somebody had scrawled, ''If you're not, call 822-2423.''
The lengthily loquacious Hubert H. Humphrey, who was not actively running but available for the Democratric nomination in 1976, probably managed to laugh when Mo said, ''Well, if after 14 ballots the brokers retire to a backroom and come up with old triple H, it probably won't take cattle prods or whips to get him to the podium to make a brief acceptance speech.''
But the contender who won that year, Jimmy Carter, probably was not amused when Mo said that if Gerald Ford and Mr. Carter were the nominees and they debated abortion, ''all sides would be represented because Ford would be in the middle and Carter would be on both sides.''
Mo could call a press conference or sit down at breakfast with reporters and an hour could go by before anybody remembered to ask a businesslike question. But beneath the banter there was serious man, the kind of liberal who is sorely missed by the Democratic Party today.
He specialized in bringing people together, rather than driving them apart. He tried to get them to compromise on what was good about progressive legislation and party policy, without rule-or-ruin insistence that a given caucus's position must prevail, no matter what.
Asked who the ideal Democratic candidate would be, he suggested someone named Franklin Roosevelt Fitzgerald Kennedy Jones. In his attitudes, he came as close as anyone to filling that large bill. Unlike those Democratic heroes, he did not make it to the White House. He tried to replace elderly Speaker John McCormack in 1968, and didn't make that, either.
Nor did he always succeed in his legislative causes. After he announced his presidential bid, a respected political writer said many of his causes showed ''a depressing strain of failure.'' Among those, he listed strip-mine controls.
But being beaten twice on strip-mining by presidential vetoes and heavy industry lobbying didn't mean he was a failure. He kept trying, and in 1977, after his losing presidential effort, he and other determined legislators passed landmark controls and President Carter signed them.
Former Rep. Dick Bolling of Missouri, an astute student of how Congress works, called Mo ''one of the few really good legislators up here, with the right mixture of idealism and pragmatism.'' Demonstrating that pragmatism, when Mo saw he was being painted into the left corner of the 1976 primaries, he announced that he was dropping the word ''liberal'' from his vocabulary. From then on, he would be a ''progressive.''
The label he and others had worn so proudly had been defiled in the Sixties and early Seventies by those who made ''liberal'' synonymous in the public mind with selfishness, irresponsibility and intolerance of others' point of view. But Mo made clear that he was just dropping the label, not the causes: Most people, he said, still wanted national health insurance, government spending to create jobs, cutting tax loopholes, protecting the environment and reducing the military budget.
Once that 1976 election was over, he went back to working for those causes without caring what anybody called him. Yet he kept getting re-elected, at the same time Arizonans were sending Barry Goldwater, ''Mr. Conservative,'' back and back again to the Senate.
That was not because Mo was liberal. It was more because he was a dedicated representative of his district. And more than that, it was because he brought a sense of humor to politics, making it possible for men who disagreed about serious matters to enjoy doing the people's business together. That's what the ++ pragmatic idealists who thought up this country hoped for long ago.
Ernest B. Furgurson is associate editor of The Sun.