"He hasn't changed his core beliefs as to what needs to be done," says Sen. Jon Kyl, R-Ariz., who is active in McCain's presidential campaign. "But he recognizes that until there is better evidence of enforcement, people are not of a mind to look to other solutions."
McCain's political prowess was evident in 1982 when, with few Arizona ties, he won a hotly contested congressional seat. Later, he weathered a political typhoon as a player in the Keating Five scandal and handily won re-election to the Senate. He was able to defeat the better-financed Bush in the 2000 New Hampshire primary by nearly 20 percentage points.
One chief asset is McCain's media savvy. Packing his campaign bus with reporters bolstered his long-shot 2000 campaign and made the Straight Talk Express a modern American political icon. Media allies helped him push his McCain-Feingold campaign-finance reform legislation into law in 2002 over the reservations of Bush and congressional GOP leaders. Frequent appearances on the Sunday public-affairs programs keep McCain in front of TV viewers when tight campaign dollars limit his advertising.
McCain's Straight Talk Express campaign bus has reached out to a new breed of media passenger: the political blogger.
"It's only natural to like a politician who is constantly accessible, who answers all of your questions and who even converses with you not as if you were an enemy or an annoyance but as if you were a guest at his house," wrote conservative Power Line blogger Paul Mirengoff, who recently traveled on McCain's bus in New Hampshire.
Sometimes John McCain delivers what he bills as the unvarnished truth with humor. Other times, he's deadly serious.
At town hall meetings on the campaign trail, McCain is funny, self-deprecating and irreverent. He cheerfully takes on all challengers in the crowd.
Debates have proved a mixed bag for McCain. When he's "on," he's tough to beat. Too often, though, at least in the early debates, McCain came across as stiff and scripted.
Delivering prepared remarks presents other challenges. He is clearly uneasy reading from a teleprompter, and even well-written speeches sometimes are obscured by his dreary delivery.
"I would not let John McCain have one note card up there," says Grant Woods, a former McCain congressional chief of staff who later served two terms as Arizona's attorney general. "Just let him be himself. When he does that, he's just fantastic."
Something else doesn't always survive the translation: McCain's wisecracking sense of humor.
When McCain quipped that a Concord, N.H., high school student was a "little jerk" and was "drafted" for asking him if he worried about contracting Alzheimer's disease, the crowd roared its approval. However, many news outlets reported the remark as if McCain angrily lashed out at the teen.
When McCain jokingly sang "bomb, bomb, bomb, bomb, bomb Iran" to the tune of the Beach Boys' hit "Barbara Ann," peace activists reeled in disbelief.
McCain suggests his critics need to lighten up.
"You can't be a loose cannon, but you've got to have fun," McCain said.
Sometimes McCain's humor hits the bull's-eye. His line about missing the 1969 Woodstock rock festival because he "was tied up at the time" as a prisoner of war in Vietnam brought down the house at the Oct. 21 Republican debate in Orlando
John McCain quite literally is a student of decision-making.