WASHINGTON - Joe Biden has always been one of those people who can talk themselves out of trouble. He may at last have found the predicament that's too tough for that.

In high school, the future senator and presidential candidate used a quick tongue to compensate for not doing homework. An old classmate at Archmere Academy, David Walsh, told the Arizona Republic this spring it was Biden's ``God-given gift.``

At the University of Delaware, he was a mediocre student - 506 out of 688 in the class of 1965. He was ``trying to be the complete Joe College,`` wrote a history professor, ranking Biden average in ``intellectual achievement`` but high in ``command of English language.`` The professor nonetheless recommended the former football and baseball jock for admission to law school ``on grounds of personality and general promise.``

But Biden soon ran into trouble at Syracuse Law. He was accused of plagiarism after lifting five pages from a law review article for a course paper. But his pleading - ``I implore you, don't take my honor`` - convinced the dean to let him stay in school, take the course over, and wipe the slate clean.

Another law dean later told a prospective employer that Biden, who finished 76th in a class of 85, had been an academic ``disappointment.`` But the dean said Biden's ``confidence,`` ``general physical appearance`` and ``general speaking ability`` would help make him a natural trial lawyer.

These gifts ultimately would propel Biden to the U.S. Senate and into the 1988 presidential race. He turned to them again last week when plagiarism allegations threatened his campaign.

But this time, the more he talked the worse it got.

Biden called a press conference. He released all his academic records, and dismissed the law school incident as ``something very stupid 23 years ago.``

But it was just last month that Biden appropriated an inspirational speech by British Labor leader Neil Kinnock. Kinnock told of ancestors who played football after long days underground in the mines, who recited poetry poetry and paved the way for him to become the first in his family to attend college.

When he saw a tape of Kinnock in action, Biden said Thursday, ``it was a connect. I mean, I could tell how that man felt. That's how I feel.``

So he used it - changing the names but little else - at a debate last month in Iowa. But instead of crediting Kinnock, he told the audience he thought of it on the way to the debate.

This was his groping explanation on Thursday:

- John Harwood is political editor for the St. Petersburg Times. -

``I landed at the airport. I know, you all know, that I don't spend a lot of time, I don't spend a lot of time writing speeches. I do them on the back of envelopes. I do them, I mean I work on them, but I do them. Some of you have traveled with me and watch how I do them. . . .

``And so I was getting in the car and a young man named David Wilhelm who runs my campaign, and I said, `David, I don't have a close.' And he said, `we've prepared you seven or eight closes.'

``But, I don't agree with any of them. . . . (He said) well, why don't you do what you do on the Kinnock thing? That expresses what you feel.' And I said, `You're right.' I said, `You know, thinking about it, that applies to me.' And that's honest to God true what happened riding over to the debate.``

At this point, Biden turned to his press secretary and asked if the named aide had, in fact, been in the car with him. He had. Whew!

Biden acknowledged Kinnock's language didn't fit his family perfectly. His father was in used car sales, his grandfather was a mining engineer. But he had been told and ``assumed`` that other relatives had worked in the mines. And, ``to make it clear,`` members of his mother's family had, indeed, been to college.

He had used some old Bobby Kennedy lines, too, but blamed a speechwriter for it. The suggestion of pilfering here was especially troublesome, since Biden's central campaign theme is an appeal to idealism that harks back to great Democratic struggles of the 1960s.

Thus ``the complete Joe College`` awkwardly tried to explain just where he stood back then:

``During the 1960s, I was in fact very concerned about the civil rights movement. I was not an activist. I worked at an all-black swimming pool in the east side of Wilmington, Delaware. I was involved, I was involved in what they were thinking, what they were feeling. I was involved, but I was not out there marching. I was not down in Selma, I was not anywhere else. I was a suburbanite kid who got a dose of exposure to what was happening to black Americans in my own city. . . . It was a revelation and it appalled me.

``I am not culturally one of those guys who like to - I don't fit very well because I'm not a joiner. I don't go out, I'm not very, I was out of sync . . . by the time the war movement was at its peak . . . I was married. I was in law school. I wore sportcoats. I'm serious. What you all don't seem to understand - some of you, I think, you understand it, but I don't think you're really being - well, I won't characterize it.

``Now look: You're looking at a middle class guy. I am who I am. I'm not big on flak jackets and tie-dyed shirts, you know, that's not me. I'm serious.``

He said it was ``bizarre`` that reporters ask him about such things. His family was most important, he noted. ``You know, I mean, I hated law school. I really did.`` But he was a fine lawyer who always gave clients their money's worth - ``Ask anybody in Delaware.``

It was an unsettling, emotional performance, hardly one to inspire confidence in a prospective leader of the Free World. He was lucky that only brief snippets were shown on network television.

Some political professionals believe his chances are already shattered. One remarkable aspect of today's presidential politics is how quickly wounded campaigns die.

Biden suggested that a treacherous rival was responsible for the embarrassing disclosures. Aides to other Democratic contenders, recalling Watergate tricks, pointed toward the GOP.

Kathryn Murray, communications director for the Republican National Committee, only chuckled at the suggestion.

``With Democrats like Joe Biden, we don't need to shoot too many arrows,`` she said. ``Those are clearly self-inflicted wounds.``

At the University of Delaware, he was a mediocre student - 506 out of 688 in the class of 1965. He was ``trying to be the complete Joe College,`` wrote a history professor, ranking Biden average in ``intellectual achievement`` but high in ``command of English language.`` The professor nonetheless recommended the former football and baseball jock for admission to law school ``on grounds of personality and general promise.``

But Biden soon ran into trouble at Syracuse Law. He was accused of plagiarism after lifting five pages from a law review article for a course paper. But his pleading - ``I implore you, don't take my honor`` - convinced the dean to let him stay in school, take the course over, and wipe the slate clean.

Another law dean later told a prospective employer that Biden, who finished 76th in a class of 85, had been an academic ``disappointment.`` But the dean said Biden's ``confidence,`` ``general physical appearance`` and ``general speaking ability`` would help make him a natural trial lawyer.