After all these years of believing he could influence national politics, Richard Douglas Llamas thought he knew a U.S. senator's high sign when he saw one.

Sitting in the Senate gallery last February during the impeachment trial of President Clinton, Llamas said he saw Sen. Edward M. Kennedy (D-Mass.) give him the nod. At that moment, he recalled, Sen. Jesse Helms (R-N.C.) smiled and Sen. Pete V. Domenici (R-N.M.) laughed.

And then the lonely, private drama of a fanciful political junky intersected, however trivially, with American history.

Llamas stood up and shouted: "Good God Almighty, take the vote and get it over with!"--bringing the trial to a momentary standstill.

Yesterday, a Superior Court jury convicted Llamas of one misdemeanor count of disrupting Congress. He could receive a maximum penalty of six months in prison and a $500 fine.

Strange testimony during the two-day trial answered some of the questions that immediately arose over Llamas's actions. In that brief period when everything connected to the Lewinsky affair was intensely scrutinized, people wondered what motivated the gallery orator. His words seemed to express succinctly the disgust that polls indicated many Americans felt at the whole mess.

Yesterday, after the trial was over and the jury was dismissed, there was another answer about what motivated Llamas, an explanation that was more prosaic and more sad.

At trial, he looked avuncular, professorial, with a thin gray mustache, glasses and a balding crown. He wore the same charcoal gray pinstripe suit he had donned the morning of Feb. 4, before he took the bus from his room without a kitchen on 13th Street NW to the Capitol.

A few weeks after his minute in the spotlight, Llamas, 49, was hit by a car, and now the Navy veteran and unemployed carpenter uses a wheelchair and lives at a Veterans Administration nursing home.

He calmly told the jury his story.

Ever since he came to Washington about five years ago, he has closely monitored the fate of the nation. He has sent dozens of handwritten letters to members of Congress, the president and other officials. By studying these leaders in newspaper photographs, and during many visits to the Capitol, he could tell they were listening to him.

About 4:40 p.m. on the fateful day, Chief Justice William H. Rehnquist was taking a roll call vote on a procedural matter.

"All I heard was just arcane, parliamentary procedural votes and maneuver after maneuver. I had become very much irritated by this," Llamas said.

"I had this welling up of emotion and feeling, after so many years and so many umpteen millions of dollars of investigation. . . . I felt I was speaking for the overwhelming majority of the American public."

He was cooperative with the arresting officers. He told them that Sen. Barbara Boxer (D-Calif.) would bail him out. She did not.

He insisted to the jury that he had never intended to disrupt the proceedings, which was legally significant because he could not be convicted unless he had that intention. He said his intention had been only to advise the Senate, as he had been signaled to do.

This was a "bizarre" story, Llamas's court-appointed attorney Michael Madden conceded during his opening statement. Some might call it "ludicrous," he said. But Llamas really believed it, he said.

And it went unchallenged. Assistant U.S. Attorney Barton Aronson certainly wasn't going to beat up on this earnest, soft-spoken man and gamble with the jury's sympathies. Judge Neal E. Kravitz and the 12 jurors listened with grave respect. It all felt a little like the courtroom scene in "Miracle on 34th Street," in which the State of New York concedes that Santa Claus exists. "Believe all of it," Aronson told the jury in his closing.

But remember, added the prosecutor, there were 97 other senators who did not signal that they were interested in an interruption. And indeed, Llamas must have intended to interrupt the proceedings, because if the senators did not stop and listen, they never would have received his message.

It took 45 minutes for the jury to agree.

After the jury was dismissed, talk turned to sentencing. Madden raised the subject that, for reasons of strategy and politeness, no one had dared speak until now.

Llamas "has a long history of mental treatment" and has been diagnosed with bipolar disorder and "delusional thinking," Madden said.

Llamas took the verdict in stride. "I kind of expected it," he said outside the courtroom, while asserting he is not delusional.

But for his attorney, he was alone. His family is in California, he said. He learned from a reporter that spokesmen for Kennedy and Boxer denied their bosses had ever heard of Llamas.

Of course a staffer is going to say that, Llamas said. "It's only been the senators who know what I've been attempting to do."

Which is?

"I'm trying to get Congress moving in a positive direction so that we can have a future in this country."

He will be sentenced on Sept. 10.