IT'S FLAG DAY. TIME TO CELEBRATE the poet who penned the immortal "Star Spangled Banner," Francis Scott Key, a grade- school history-book idol and the man known in Washington as Frank Key.

The poet was a lawyer, and not a bad one at that. Key made his debut in 1807, successfully defending Aaron Burr's co-conspirators against treason charges. Congress forgot its business and went to the court on the days of the trial. All eyes were on the three-man defense team of which Key, only 27 years old, was the youngest.

In 1825 he argued against the slave trade in one of his many cases before the Supreme Court. One spectator noted Key's "bright ethereality of aspect and a noble audacity of tone which pleased while it dazzled the beholder." He was "thrilling"; he was "electrifying"; and he lost. In one of his less memorable decisions, Chief Justice John Marshall held that the slave trade was not against international law.

Key got a reputation for emphasizing style over legal substance, but in Washington, style can go a long way. A congressman accused Sam Houston of defrauding the government. Houston, in turn, caned the congressman, and the House of Representatives dragged him to trial. Key defended Houston and attacked not so much the Congress as the press, which had portrayed Houston as a brute.

Not so, cried Key, insisting that Houston "had once, indeed, an arm fit to execute the strong impulses of a brave heart -- but that arm he had given to his country. On the field of one of her most perilous battles it had been raised in her defense . . ." Frank Key's defense changed Houston from bully to crippled vet, and Congress let him off with a reprimand.

Key's performance impressed Houston's buddy, President Andrew Jackson, who appointed Key U.S. attorney for Washington. Key promptly set about closing down the gambling dens that lined Pennsylvania Avenue.

In August 1835, a slave, John Arthur Bowen, tried to kill his owner, the venerable Mrs. Anna Thornton, widow of the designer of the Capitol. The slave's mother stopped him. The incident, however, ignited rioting against free blacks in Washington, and Key was one of many who blamed abolitionist newspapers for inspiring Bowen's actions.

Specifically, Key used a common- law libel charge to jail Dr. Reuben Crandall for distributing "incendiary" abolitionist newspapers. Crandall contended that he had only used them as packing paper for his move to Washington and that someone had inadvertently picked them up in his office and passed them out around town.

U.S. Attorney Frank Key wasn't buying it. He showed the jury newspaper pictures of whites whipping black children, and he charged that they could only be meant to incite illiterate blacks. No one could read Crandall's propaganda, Key maintained, "without feeling his blood boil at the cold and heartless sneers at the beauty and chivalry of the South."

Clearly, this wasn't Frank Key's finest moment. Patriots probably won't want to remember it on Flag Day. On the other hand, after Key's pathetic plea in defense of the South, the jury deliberated for only an hour in the case against Crandall and returned a verdict of not guilty. ::