The clashing worlds of razor-sharp discipline and campaign fatigue are an ever-present factor in the daily lives of presumptive presidential nominees Barack Obama and John McCain.

In a 24-hour news cycle, words are not “just words.” They matter.

Obama knows he cannot afford another “sweetie” directed at a female reporter– or reference to his grandmother as having “typical white-person” traits, as he made in a radio interview.

And you won’t hear McCain singing “bomb, bomb, bomb, bomb, bomb Iran” to the tune of the Beach Boy’s “Barbara Ann” between now and November.

Despite grueling hours and a complete lack of sleep, candidates and their wives know, now more than ever, to measure their words.

But what about the campaign surrogates who are dispatched to the heartland or to a Sunday morning news show to represent them?

The role of a surrogate comes into play simply because there is only so much ground a candidate and a spouse can cover. A surrogate’s job is to spread the campaign’s reach across the country. Done well, they can maximize the candidate’s time when only so many days and months remain before Election Day.

Surrogates can be extremely effective; typically, they are high-profile personalities, such as people who have run for president before, or an athlete or a rock star. But with that effectiveness, a peril always exists that surrogates have their own agendas, or make mistakes, or are not as disciplined as the candidate who is running for president 24 hours a day.

That is clearly what happened with retired Army general Wesley Clark two weeks ago, when his opinion of McCain’s leadership qualifications became a 48-hour news story.

GOP strategist Kevin Madden says the surrogate’s job is to be a passionate advocate for the ideas and attributes of a candidate. “Surrogates need to remember, it's not about you, what you think, or what you believe, it's about the candidate.”

In other words, don't be an analyst.

Another really important rule for a surrogate is to do no harm; don't create news with a screw-up or a controversy. Yet ask any surrogate, and that is easier said than done. Continued...