For long, anxious days now, the presidential candidates have been prepping for the critical debates that begin tomorrow, with two more to follow.

Probably more anxious than the candidates themselves (because both the candidates are veterans of debates, and television performances before mass audiences) are the platoons of "handlers" and "trainers," and sound-bite polishers who have been nervously pirouetting around their candidates trying to anticipate every potential gaffe and misspoken phrase, preventing every unfortunate camera angle, and generally grooming their man for perfect public performance.

Each candidate has been rehearsed and re-rehearsed in mock debate, with a tough stand-in for his opponent, testing him with the most provocative taunts. The candidate will have been immersed in enormous briefing books, covering everything from the throw-weight of North Korea's potential nuclear weapons to the caloric value of school lunches in Oklahoma. These official briefing books are dizzying in their volume and content and will have faded in memory and be of little use when the candidate gets out there by himself under the television lights with no props, no notes, no tele-prompter, and has to think on his feet before millions of viewers.

I've never briefed a president of the United States, but I routinely used to brief Secretary of State George P. Shultz before he went out to field questions from the international press. Luckily, Shultz had a prodigious memory and unflappable demeanor at which I used to marvel. But even he would occasionally be thrown by a preposterous question, as when a reporter of questionable mental balance asked him what he was going to do about his predecessor Henry Kissinger's "homosexual relationship with a Mexican bellboy whom he later murdered."

The debates between President Bush and Sen. John Kerry are being hyped as critical to the election's outcome, although they are probably more for Bush to lose than Kerry to win. We must hope that there is more substance than theater to them. Up until now in this campaign, substance has been overshadowed by an eruption of machismo over who did what in a war some 30 years ago.

Nonetheless, many voters will be influenced by how the candidates look and perform, rather than what they say.

Kerry has been a practiced debater since prep school but comes across as wordy and pedantic. The London "Economist" calls him "damnably boring." The "Wall Street Journal" says his "meandering verbosity" is an "unclear, indirect style that sometimes makes it hard for (him) to connect with audiences and leaves his words open to parsing and ridicule."

Bush has his own mangled confrontations with the English language. He cannot get his tongue properly around the word "nuclear." He's talked about "Grecians" instead of Greeks, and of "cocoa" production in Columbia instead of coca, and of "inebriating" when he meant exhilarating. But he pokes fun in an engaging way about his own "Bushisms," and he brought the house down at a Gridiron Club dinner in Washington when, after joking about his stumbles, he thanked reporters for their "horspitality."