No sir, says Larry King sadly, they don't make political scalawags like they used to.

"I'm afraid we're breeding smoother thieves who are a lot less interesting," says King, the man who has lovingly turned the chicanery of his native state into a multimillion-dollar industry called "The Best Little Whorehouse in Texas."

King's next project, with co-author Ben Z. Grant (a Texas state legislator), star John Daniel Reaves (a Washington lawyer) and producer Barbara Baine (a young entertainment lawyer and King's wife), is "The Kingfish," a one-man show about Louisiana's Huey Long to be done at the New Playwrights' Theater on Church Street from August 17 to September 9. Although regarded by some as America's answer to Benito Mussolini, Long is one scalawag who meets King's high standards.

"I'm for the S.O.B.," says former congressional staffer King, the only member of the "Kingfish" partnership who was alive - he was 6 years old - when Long was assassinated in 1935.

Before his stunning entry into politics, Long peddled silk socks and patent medicines, among other items. Two of his medicines, according to King, were called "High Papolorum" and "Low Papolorum," "which he admitted came off the bark of the same tree. To get High Papolorum, you skinned the bark from the bottom up, and to get Low Papolorum you skinned it from the top down."

On the stump in 1932, Long would tell that story on himself and add, rousingly: "And that's the way it is with Mr. Roosevelt and Mr. Hoover - do you want to be skinned from the head down or the feet up?"

Long was a good deal shrewder than Willie Stark in "All the King's Men," King and Reaves agree. Robert Penn Warren's book was "a terrific novel, but not all that historically accurate," says King. "He was not a goon," says Reaves, adding that Long had an "incredible library."

But Long's most notable virtue, as King reckons it, is that you knew where he stood: "I'm not sure what Jimmy Carter wants to do but you could tell what a Huey Long or Lyndon Johnson wanted to do."

"The Kingfish," which King has helped refashion from an initial draft by his Texas friend Grant, will draw both on Long's actual words and on a vast shared store of anecdotal memories of southern political struggles and shenanigans.

King's memories were acquired during his own long career in politics, a career launched at the age of 5, after a candidate for county commissioner (whose name, King recalls, was "Arch Bent") bought his mother's chocolate cake at a "political pie supper."

"He was the first adult to treat me like an adult," says King. "He handed me one of his business cards and asked me if I'd join his campaign."

At 25, King came to Washington with Texas congressman J. T. Rutherford, and continued to work on Capitol Hill (serving brief stints with Jim Wright and Lyndon Johnson, among others) from 1954 to 1964.

Then he started writing for a living. He began with magazine articles (and later became one of the Harpers Magazine contributors who resigned in protest over editor Willie Morris' dismissal in 1971); then came books: "Confessions of a White Racist," "The One-Eyed Man" and a nonfiction volume called "And Other Dirty Stories." Now, with "Best Little Whorehouse" under his belt, he has turned to plays.

In the living room of King's Capitol Hill home where he, Blaine and Reaves talked about their show, the author and star seemed perfectly typecast. As each other, that is.

King, with his rich Texas drawl and a beard that seems ready to leap out at you, is a one-man show all by himself. The Alabama-born Reaves is quieter and more contained. He resembles Huey Long in face and frame, but acts like a man who would not be happy atop a stump.

This bold piece of casting was committed, according to King, "after John Daniel let it slip one night that he had done a little acting. We persuaded him to show us some of his reviews."

Here the star interrupts to confess that he had carefully "scattered them out around the table like place mats."

Then came the battle to get Reaves to audition for King and Blaine. He stalled for weeks - until they finally insisted that it was now or never - he read for them and was instantly accepted.

"What he'd done," says King, "was sneak off and look at all of the newsreels of Huey Long at the National Archives."

Those newsreels, curiously, showed that Long had "an extremely high and unattractive and reedy voice" - a voice Reaves has not attempted to duplicate. But they also showed a genius at adapting to every audience's mood and at sweeping dirt-poor listeners up in the passion of his commitment to improving their lot - a committment whose sincerity King utterly accepts, while acknowledging, "There's just not any doubt that power corrupts."

Until three years ago, Reaves worked for the Federal Trade Commission, but is now in private practice, doing the preponderance of his business with the Federal Trade Commission. "The revolving door all over again," King observes drily.

"The Kingfish" will be Blaine's first try as a producer, but she has already had the gumption to knock down her husband's and her star's expansive ideas about scenery. "If we had built the set that these two wanted, it would have cost $25,000," she says. "We could sell out the whole run and not make anything close to $25,000."

Blaine and King met when she was working for the law firm of Vinson and Elkins, which then included John Connally as one of its partners. King was covering the Conally milk-price-fixing trial for Atlantic Magazine. (Connally is one colorful southern politician King can't abide: "He's the most dangerous man in America today," says King.)

The New Playwrights' Theater was chosen because every other hall was booked up, according to King and Blaine, who have ultimate visions of a national tour - with heavy southern emphasis, naturally - and a possible TV production.

All these plans will have to work around the fact that Blaine is six months pregnant. As Reaves puts it, the King-Blaine team is about to collaborate on "two one-person productions." CAPTION: Picture, Huey P. Long in 1935; Barbara Blaine, John Daniel Reaves and Larry King; by Joel Richardson - The Washington Post