Few events in our nation's history have had the emotional impact of President John F. Kennedy's shocking assassination. And few, if any, coins, have stirred the American people as profoundly as the Kennedy half dollar.

Nearly 35 years have passed since those shots rang out in Dallas on Nov. 22, 1963, altering the course -- and the fabric -- of U.S. history. But the images of that tragedy linger in our minds like an unending instant replay.

JFK's slaying clearly helped trigger the social unrest that followed -- the rioting in the cities, the protests on college campuses, the entire countercultural revolution. In a very real sense, it destabilized American society.

The Kennedy half dollar also might be viewed as a destabilizing force -- a surely unintended but ironic consequence, considering that the coin was meant not only to honor the slain president but also to serve as a symbol of national strength and continuity.

As I ponder this today, with the benefit of 20-20 hindsight (or, more precisely, 35-35 hindsight), I can't help but ask a basic question -- one that may startle some collectors: Should this coin ever have been issued in the first place?

I don't dispute for a moment that we should have honored John Kennedy on a coin. What I question is the wisdom of rendering that tribute on this particular coin.

Prior to 1964, coins of five different denominations, from the cent through the half dollar, circulated freely in our country. True, the half dollar saw far less use than its four companions, but it changed hands with sufficient regularity -- and in sufficient quantities -- to play a significant role in the nation's commerce.

The Kennedy half dollar altered this equilibrium fundamentally -- and, it would appear, permanently. From the moment of its release, it was coveted and hoarded as a handsome, inexpensive and, best of all, official government tribute to JFK. Despite enormous mintages far exceeding those of earlier half dollars, the U.S. Mint simply wasn't able to sustain the new coin in circulation.

In 1965, when silver was removed from the dime and quarter, Congress decided to keep a reduced amount in the half dollar, thereby retaining at least a token tie with the precious-metal coinage of the past. In retrospect, this too was a mistake, for it gave the American public yet another reason to continue setting aside Kennedy halves.

The escalating price of silver -- which had prompted the introduction of "clad" copper-nickel coinage -- led to the quick removal of earlier half dollars from circulation (along with earlier dimes and quarters, as well). And this, combined with the public's largely emotional hoarding of Kennedy halves, effectively deleted the largest denomination from the mix of coins being used in U.S. commerce.

If anything, the potential usefulness of a 50-cent piece has risen sharply during the last generation. With the dollar having shrunken in value, items that once cost a nickel or a dime now carry price tags of 50 or 60 cents -- possibly even $1 or more -- and a higher-denomination coin would seem to have many uses, especially in vending machines. That, after all, is why Congress authorized the new dollar coin that will make its first appearance in the year 2000.

But because of its extended absence from circulation, the half dollar nowadays is regarded not so much as something to spend, but rather as a kind of curiosity. The public has grown accustomed to using two quarters instead, and so have the nation's vendors - and it's doubtful whether either group will break this long-standing habit, even when the dollar coin appears.

What could -- or should -- our leaders have done back in 1964 in order to avoid this unhappy scenario?

To my way of thinking, the answer would have been a commemorative coin -- a silver half dollar or perhaps a silver dollar, but in any case a one-time-only issue.

This was the way we paid coinage tribute to President William McKinley, the last U.S. president prior to Kennedy to meet an untimely end at the hands of an assassin. McKinley was honored, in fact, on two different U.S. commemorative coins: the Louisiana Purchase Exposition gold dollar of 1903 and the McKinley Memorial gold dollar of 1916-17.

Commemorative coinage also was the method chosen by Great Britain to pay final homage to Winston Churchill: with a special one-time crown (or 5-shillings piece) in 1965.

Of course, McKinley's death, in 1901, predated the use of real people's portraits on regular U.S. coinage. Also, there had been a much more recent precedent for choosing regular coinage for the tribute: Franklin D. Roosevelt's death in 1945 had been marked the very next year by the Roosevelt dime.

Still, I have to wonder whether the powers-that-be wouldn't have opted instead for a one-year commemorative -- if there hadn't been a firm government policy against minting "commems" at the time.

Obviously, the policy could have been brushed aside - just as other barriers were -- under the emotional impetus of the moment. It's my impression, though, that because of the suspension of commemorative coinage nearly a decade earlier, little if any thought was given to this alternative.

Imagine how different our coinage -- and U.S. coin collecting -- might be today if the Mint had issued a special half dollar or dollar in 1964 to honor President Kennedy and continued yearly production of Franklin half dollars for circulation.

The coin would have been sought every bit as eagerly as the one that did emerge -- possibly even more so, given its limited nature. It probably would have stimulated wide- ranging interest in earlier U.S. commems, and might well have prompted the issuance of more in the years that followed.

Meantime, the Franklin half dollar would have become a longer, more interesting series with 40-percent silver and non-silver varieties joining the earlier 90-percent silver issues. And, in all likelihood, we'd still see these half dollars routinely in circulation.

All this, of course, falls within the nebulous, wishful realm of the might-have-been.