Ronnie Dugger, noted author and publisher of The Texas Observer, and Maury Maverick Jr., lawyer, newspaper columnist and heir to a surname that defines nonconformity, are each in the pantheon of Texas liberals. That says a lot and not much at all at the same time, for as former Observer editor Molly Ivins says, being on the liberal left in Texas is kind of like being an early Christian.

Thin as the ranks of believers might be, Dugger and Maverick carry an intellectual force that helps set the agenda for political discourse in Texas.

Dugger has been searching for answers to moral questions here since the founding of The Observer three decades ago, when, as its kid editor, he cruised the state in a 1948 Chevrolet, banging out stories of injustice from wherever it was that his radiator or fan belt gave out. Maverick, great-grandson of the man who refused to brand his cattle, and son of one of the Young Turks of the New Deal, has accepted his hell-raising heritage with vigor, so much so that when his father was dying he called young Maury to his deathbed and growled: "Maury Junior, I want you to know you didn't turn out to be as big a horse's ass as Elliott Roosevelt."

The topic that Dugger and Maverick have focused on this year is Nicaragua, and they find themselves in spirited disagreement. Their dispute has gone public in the pages of The Observer, revivifying a journal that to some had slipped into a quiescent period and provoking some nastiness, a bit of posturing, much soul-searching and a whole lot of letter-writing among the Texas cognoscenti.

The essence of the argument is this: Dugger believes Nicaragua's President Daniel Ortega has gone too far in suppressing civil liberties, and says that it is imperative for the American left to press the issue; Maverick contends Nicaragua is not as repressive as Dugger fears, and that in any case civil liberties are beside the point until the Sandinistas are free from the national security threat posed by contra forces backed by the Reagan administration.

On the cover page of last month's Observer, in dueling columns under the banner headline "Oh Nicaragua," Dugger and Maverick took each other on.

"People who support any revolution against tyranny without inquiring whether it will create a new tyranny incredibly ignore history," wrote Dugger, in a revised version of a column he first wrote for the Los Angeles Times. He recited the lessons of Lenin in the Soviet Union and Castro in Cuba, and suggested that American civil libertarians should undertake a fact-finding trip to Nicaragua to confront the Sandinistas "frontally and publicly" about civil freedoms.

He concluded: "Granted, as long as the Reagan administration presses the war against Nicaragua, Ortega will have his plausible reason for temporary repression. But if he is just another Lenin, just another Castro, just another dictator, we had all better find this out before, once again, the American left betrays the cause of civil liberties abroad."

Maverick began his response: "Ronnie Dugger, an old and close friend of mine, is one of the bravest journalists in the history of Texas, but what does Dugger mean when he writes" that only a fool would trust Ortega? Maverick recalled the moments of national crisis when U.S. presidents temporarily repealed civil liberties: when Lincoln suspended rights of habeas corpus during the Civil War, when Roosevelt placed Japanese Americans in internment camps during World War II.

"Last bite at the apple," wrote Maverick. "In your heart of hearts, what would you do if you were Daniel Ortega? Would you be a 'nice guy' like Salvador Allende of Chile and let the CIA destroy your government and maybe your life? Isn't what happened to Allende a lesson of history?"

In a box on Page 3 of The Observer, editors Geoffrey Rips and Dave Denison solicited letters from their readership and said of the decision to publish the Nicaragua commentaries: "We have decided to stir up the ant bed."

Indeed they did. Rips himself stirred things up by writing an editorial that sided not with his boss but with Maverick. Rips derided a "new force in the foreign policy debate" composed of what he called "New Leftish defectors" who were abetting the Reagan administration push for more contra funding. Interviewed this week, Rips criticized Dugger directly. "What I object to is it seems that the fate of American liberals is of more concern to Dugger than the fate of 4 million Nicaraguans."

Rips seemed to have The Observer readership on his side. Of the dozens of letters that have arrived at the biweekly's office here in recent days, only about one in five agreed with publisher Dugger. Fourteen of those letters were published in the most recent issue, and a lively mailbag of dispatches they were:

*"The right-wing drift of Ronnie Dugger, apparent since his Cold War liberal anticommunism of the Vietnam War, has become a reactionary landslide." -- Rod Davis. Austin. Former Observer editor.

*"I do not mean to imply that it is out of line to be critical of Nicaragua, but I do think it is a little silly. It is our government and our tax dollars that is paying murderers and thugs to wipe out their nation's infrastructure." -- Kenneth Pardue. San Antonio.

*"What is this? Maury Maverick Jr., great civil libertarian, liberal leader and human rights activist, reincarnating himself as Daniel Ortega's personal Ron Ziegler?" -- Thomas A. Prentice. Austin.

*"Since our days at the University of Texas, I had had an extremely difficult time finding any political position taken by Ronnie Dugger with which I can agree. Maury Maverick has finally rescued me. I called him several nights ago to tell him so." -- Hugh H. Meyer. Hondo.

*"I believe that the obligation of all those who care about a democratic Nicaragua is to make it clear to the Sandinistas that at the very least, the measures they take to protect themselves must be proportionate to the real threat." -- Gara LaMarche. Austin. Executive Director, Texas Civil Liberties Union.

Dugger, who now lives in New York, returned to Austin last week to receive an award for The Observer from the Texas Civil Liberties Union. In accepting the honor, he noted that there are no sacred cows at The Observer, "and if you've been reading us lately, you know that includes the publisher." He said he had no problem with Rips taking an opposing view.

"The Observer calls itself a journal of free voices," Dugger said in an interview. "That it is. The balance of power between editor and publisher is as follows: I hire and fire. The editor is free to publish whatever he or she wants. There is no hammer from me. The editor is as free as he or she has the courage to be. It is a vigorous freedom."

Dugger said that Rod Davis, whom he fired in the early 1980s, and Greg Olds, with whom he had a parting of the ways in the early 1970s, had become disenchanted with The Observer's fundamental belief in the electoral process. "The contract between myself and the editor contains freedom within that continuum," Dugger explained.

In staking out his position on Nicaragua, Dugger said he realized he was vulnerable to charges that he was helping the Reagan administration's position in Central America, which he said he deplores. "I realize the vulnerability there," he said. "But that has led to what I think has been a kind of cowardice from American liberals who believe in civil liberties. They are afraid to apply them to Nicaragua. The question is, how is the Sandinista directorate going to come down when Reagan stops giving them the excuse? That's the question, and I think it's irresponsible not to face it, even in the middle of a revolution."

Dugger said his editor, Rips, was correct in sensing his concern about the image of the American left. "I don't mean to be concerned about this, and not that; there are different weights to concerns," said Dugger. "But I think liberals and progressives had damn well better worry about the integrity of the movement. The integrity is in doubt whenever questions of civil liberties are not confronted."

Maverick, for his part, says that Dugger's problem is that he has never been to Nicaragua. "I love Ronnie," said Maverick. "I know that he has always had, and rightfully so at times, a deep apprehension about the lack of press freedoms in communist societies. But I've been there. He hasn't. I talked to 50 Roman Catholic priests and nuns who were serious about Catholicism and deeply committed to the revolution. Nicaragua is not Czechoslovakia or Cuba, and if we stop kicking them around like a bunch of cur dogs, that will become apparent."

Both men think the debate has been a healthy one for Texas liberals and good for The Observer, whose circulation and clout have diminished somewhat since the days when it was the home base of such illustrious writers as Dugger, Billy Brammer, Ivins, Kaye Northcutt, Willie Morris and Jim Hightower. Ivins, the editor from 1970 to 1976, now writes a column for the Dallas Times Herald. "Hoo boy, darlin', there's much slicing of hip and thigh goin' on," she said of the Nicaragua debate. "I love it! This is what The Observer is for."