It's a sure bet the Daniel Popeo does not top any hit parades in Peking. Most criminals probably don't care too much for him, either. And Washington bureaucrats aren't inclined to write him love letters.

Popeo is the executive director of the Washington Legal Foundation, a right-leaning public interest group that in the past year has:

Won a decision from U.S. District Court here that Jimmy Carter's termination of America's defense treaty with Taiwan was unconstitutional because the Senate was not consulted.

Sued criminals on behalf of victims of violent crimes, seeking to attach any assets, wages, literary or movie rights the criminal might own or realize.

Blasted regulatory agencies as insensitive to the average American and sued for relief from government rules some find outrageious.

"When you hear the phrase 'public interest' a few years from now," vows Popeo, "you'll think of it a little differently."

Popeo is a 29-year-old attorney who began working in the government after earning his law degree from Georgetown Universtiy in 1975. For two years he traveled the country on behalf of the Interior Department, often closing down businesses that violated health and safety regulations.

"I had my fill of it because I shut down one too many mom-and-pop operations," says Popeo. " saw the tremendous unbridled power these unelected officials in the bureacracy have. They have the master-servant theory all mixed up; they think the American public is the servant and they are the masters. Well, they're wrong."

Popeo gets exercised when he talks about smug bureaucrats and callous criminals, and he apologizes for preaching. But, he's convinced the pendulum of justice has swung too far toward the rights of the oppressors and away from the oppressed. The antique blasting machine he keeps on his desk seems an appropriate symbol for the seven-days-a-week enthusiastic pitchman's approach he brings to his mission.

"You have to be a promoter," says Popeo, who earns more than $25,000 a year running the foundation that counts 73,000 members who contribute to the $800,000 annual budget. "that's what public interest law is all about -- you will make a difference, you will make a change. We throw a stone into the pond, and the ripples can be felt in oceans all over the world."

One big stone Popeo threw along with Sen. Barry Goldwater (R-Ariz) and 25 members of Congress was the challenge to the president's decision to end America's defense treaty with Taiwan. Attorney General Griffin Bell argued the president's side and lost last month; the Court of Appeals is expected to rule in the next couple of weeks, and the case could wind up before the Supreme Court. Currently the law of the land is U.S. District Judge Oliver Gasch's order that the State Department not take any steps to abrogate that treaty with Taiwan Jan. 1, 1980, as planned.

"It cuts both ways," says Popeo, perhaps to soften the nickname, "Ralph Nader of the Right," given him by a trade publication. "What would happen if you got a conservative president who wanted to terminate a treaty such as the Panama Canal agreements against the advice and consent of the Senate?"