A scrappy fighter

He has used fairly consistent techniques during his roughly 30 debates on the national stage: he is an aggressive competitor who scolds his opponents and grins when he scores.

A review of several of McCain’s debates shows that he is most comfortable and authentic when the subject is foreign policy. And in a stroke of good fortune, foreign policy is the topic for Friday, the first of three 90-minute debates with Senator Barack Obama.

Voters give higher marks to McCain as a potential commander in chief, and Obama should expect McCain to question his credentials for the job at every turn — and to distort his views.

McCain is likely to steer the conversation, as he has in past debates, to his captivity in Vietnam. He uses short, active verbs that project strength, and he can connect with audiences using down-to-earth language. He was one of 10 Republicans on stage when the primary debates began in May 2007, but he managed to stand out with one vivid remark. Saying he would do “whatever is necessary” to capture Osama bin Laden, he declared, “I’ll follow him to the gates of hell.”

“McCain’s major weakness is looking wooden, and when he’s out of his comfort zone, his sound bites become weaker and his evasions of questions become more obvious,” said David Lanoue, a political scientist at the University of Alabama and an expert in presidential debates.