T HAPPENED IN a tired old sports arena in Omaha, Neb., during the 1988 vice presidential debate between the Democratic vice presidential candidate, Lloyd Bentsen of Texas, and Senator Dan Quayle of Indiana. Quayle had invoked the name of John Kennedy. Bentsen turned, paused, looked at his opponent a bit disdainfully and said, ''I knew Jack Kennedy, Senator, and you're no Jack Kennedy.''
I was seated about 6 feet away behind a blue flat out of camera view, so I had to whisper as I turned to a member of my production crew and said, ''That's all anyone will remember about this debate.''
That moment will be in my mind as I watch tomorrow's debate at the University of Massachusetts.
Most of my colleagues in the press room will be listening with one ear, typing furiously, keeping track of the candidates' missteps, factual omissions, and hyperbole, their eyes focused on their laptops. I'll be doing what smart viewers at home will be doing: watching more than listening.
They and I will be looking for the candidates' presidential qualities - how they speak, how they act toward each other, when they smile or frown, what their body language is when they're on camera and what it is when they think the camera's not on them. Remember George Bush checking his watch at the 1992 debate, as if he had somewhere else to go?
At every debate there is a line or a moment when personal qualities stand out and reveal something of the carefully coached man inside.
It's often that moment viewers remember. It's that moment when they are persuaded to vote for this man not that one. It's that moment that counts for more than a ton of briefing papers on issues.
Think of Michael Dukakis fumbling to answer Bernard Shaw's question about rape in 1988 or Ronald Reagan saying ''There you go again'' to Jimmy Carter in 1980.
All of which underlines the fact that there are two ways to watch a debate.
The wrong way is the way many politicans, journalists, and public policy analysts watch: with position papers in hand, comparing the candidates' stands on Social Security, prescription drug coverage, national defense, education - the major issues they have been debating throughout the campaign.
That's because policy wonks and journalists value truth and consistency and think politicians ought to as well.
But as fascinating as the debate will be for those who care deeply about such issues - and we all should, even if we don't - many voters, including some tuning into the campaign for the first time, will use another yardstick by which to judge the candidates.
Call it the impressionistic or holistic approach.
They will pay attention to things like body language, tone of voice, ability to handle the pressure of the occasion, sense of humor, ability to influence, persuade, rebut. Those are all qualities we think our presidents ought to have.
Somehow those attributes don't seem to impress the talking heads who appear on screen a moment after the candidates leave the stage. Maybe that's the reason they are often wrong in their instant judgment about who won and who lost.
Diana Carlin of the University of Kansas, the leading researcher of presidential debates, says that viewers she has studied are suspicious of detailed policy proposals and often use the word ''hire'' as they reflect on how they watched a debate - hire, as in which politician impressed them enough to be hired for the job of president. Viewers are quick to forgive small missteps because no one is perfect, and they trust their impressions of the whole man.
TV debates are the World Series of politics. Everything is on the line. As the old three-network hegemony has eroded and scores of cable channels have split the television audience into tiny slivers, a presidential debate ranks with a series game as one of those rare moments when we all share a national experience.
Wise viewers of tomorrow's debate will ignore the chattering class's judgments about which man dotted the i's and crossed the t's on the talking points in his briefing book. They will trust their first impressions and make their judgment based on the intangible factors they would use if they were judging a job candidate.
Ed Fouhy was executive producer of the 1988 and 1992 presidential debates.
