Forgotten Giant : HENRY CLAY: Statesman for the Union, <i> By Robert V. Remini (W. W. Norton & Co.: $35.00; 832 pp., illustrated)</i>

The fastest way to empty a room these days is to switch on the television to a congressional debate. There is nothing quite like the harrumphing, molasses/tobacco/bourbon-oiled tonsils of a windy legislator, especially if he comes from that part of the South where potential demagogues are trained in elocution. Is it just the public’s distaste for braying politicians or is it perhaps that oratory no longer is an art to be relished only by the immediate listeners?

Yet politics historically has attracted some of history’s spellbinders, from Demosthenes to Winston Churchill, Cicero to Adlai Stevenson. Consider the influence of one of the truly great public speakers, Henry Clay, who dominated the first half of the 19th Century. He was, most listeners agreed, unlike any other speaker. For example, Clay could not touch Daniel Webster when it came to declamation.

“His style was totally different. He was more a debater than an orator. There were not the majestic flourishes in the grand manner that oratorical eloquence normally dictated. Instead, there was something intimate in the way he spoke, something insinuating, friendly, warm--and highly emotional. Although he was frequently playful, witty and loose, he could also slash, cut and gouge when necessary. Invariably dramatic, if not flamboyant, he regularly mesmerized his audience with his histrionics. . . . In Congress he instinctively knew how to appeal to the galleries and bring them to their feet, shouting and clapping.”

Thus we can understand the scramble for seats on Jan. 20, 1819, when Henry Clay stepped into the well of the House of Representatives and ripped into Gen. Andrew Jackson for his overzealous military blood-letting at the conclusion of the War of 1812. Clay, Speaker of the House, was piqued at not being named Secretary of State by President James Monroe (thus assuring him the next presidential vacancy). He decided to attack Monroe through Jackson.

“Long and lean of body, his eyes mischievously darting from side to side, and his wide mouth slightly curved into a deceptive smile, Clay proceeded to display the full range of his extraordinary speaking talents. He was eloquent and witty, dramatic and playful, knowledgeable and devastating,” Robert V. Remini writes in this powerful, long-overdue biography of an almost-forgotten statesman.

After first disclaiming any personal animosity toward Jackson or Monroe, Clay started after Jackson: “It was a blistering assault. Despite his careful attention to all the niceties of gentlemanly conduct dictated by his position and authority as Speaker, he nonetheless crucified poor Jackson.”

The spectators, however, felt cheated when Clay stopped speaking after only two hours, having lost his voice. While undoubtedly a masterpiece of invective, this speech was a turning point in Clay’s political ambitions. In spite of the power of Clay’s passion, the persuasiveness of his arguments, he had picked the wrong whipping boy.

“Jackson was a very excitable and vengeful man who could not abide criticism. Not from anyone. To attack him, to mock him, to make him the butt of nasty innuendoes”--for such was Clay’s savage gift--was to stir in Jackson “a ferocious and full-blown hatred for Henry Clay.”

Jackson, Remini writes, “could hate with a biblical fury, and he now directed it totally against Speaker Clay. He also knew how to exact revenge.” Clay “had committed against General Jackson the first of a series of mistakes that would forever keep him from the White House.”

Remini, professor of history at the University of Illinois in Chicago, has written about Clay’s great enemy in “The Life of Andrew Jackson.” Remini knows Jackson well, having written more than a dozen books about Old Hickory. Yet he treats Clay with such affection and care that after half a century of being a vague name in pre-Civil War American history, Henry Clay springs to life in all his fascinating brilliance.

An adroit duelist (he defended Aaron Burr shortly after the Vice President killed Alexander Hamilton in a duel), a gambler, and a social lion, Clay cut a swath through Washington society with his eloquence, his charm with women and his boisterous drinking, carousing and swearing.

In Remini’s delightful biography, he emerges as a rare member of a second generation of Founding Fathers, having been born while the Revolution was still smoking in 1777. He grew up in Virginia and as a young student of the law, attracted the attention of George Wyeth, the professor who taught the law to Thomas Jefferson, John Marshall and James Monroe; Wyeth also was a signer of the Declaration of Independence.

Early in his career, Clay decided that he preferred the heated debate, wheeling and dealing of the House of Representatives to the boring rumblings of the Senate. Speedily elected Speaker of the House, Clay was the first to mold that job into one of power. He enlisted young representatives from the South and from the West (Clay had moved his family to Kentucky) who were snorting fire for a war with England coupled with an invasion of Canada. He forged this group into the “war hawks,” who bullied President Madison into declaring war on Great Britain.

This same instigator of the war then was named to the peace delegation that ultimately forged the Treaty of Ghent in 1815, obtaining from England reassurances that secured the sovereignty of the United States. While in England and France, Clay hobnobbed with lords and counts and dukes, gaining for himself the nickname, “Prince Hal.”

Henry Clay died in 1852, thwarted in his desire to become President. However, as Remini reminds us, Clay’s final victory was in the Compromise of 1850, an act that delayed secession and war at a time when the South would easily have achieved independence.

This is a lucid, dramatic revelation of a forgotten giant of American history, illustrating the complexity of the man whose fame as speaker, lawyer and statesman is balanced against his outlandish social life and his driving obsession with becoming President. Remini understands the value of a chatty, relaxed narrative that should appeal to general readers while at the same time satisfying the demands for historical accuracy and thoroughness.