All Things Considered also looked at Democrat Barack Obama's temperament in advance of the first presidential debate.
In a presidential election, candidates spar about issues. But in the end, voters make a decision about character. Who do they believe is better suited to lead the country?
Temperament is just one of the many stark differences between Democrat Barack Obama and Republican John McCain. One candidate is cool and cerebral, while the other is bold and visceral. There's no doubt how McCain would like to be seen — in the same mold as his passionate presidential heroes, Theodore Roosevelt and Harry Truman.
McCain's own temperament has been dissected by authors, political analysts, opponents and McCain himself — who has recounted how he started out as a cocky, rebellious Navy flyer who proudly collected hundreds of demerits at the Naval Academy.
"As a young man, I would respond aggressively and sometimes irresponsibly to anyone whom I perceived to have questioned my sense of honor and self-respect," he said.
"Those responses often got me in a fair amount of trouble earlier in life."
But in the second half of McCain's well-known narrative, he found the true meaning of honor and a calling greater than his own self-glory when he was captured and tortured for five-and-a-half years as a prisoner of war.
"I once thought I was man enough for almost any confrontation," McCain said. "In prison, I discovered I was not. I tried to use every personal resource I had to confound my captors, and it wasn't enough in the end. But when I had reached the limit of my endurance, the men I had the honor of serving with picked me up, set me right, and sent me back into the fight. I became dependent on others to a greater extent than I had ever been before. And I am a better man for it."
In prison, McCain's youthful resistance to authority became the source of his inner strength and resilience. The story of McCain's personal courage — whether he's taking on his Vietnamese captors or corrupt members of his own party — is at the core of his political message, and it was the major theme at his nominating convention last month.
Former Tennessee Sen. Fred Thompson described the torture that McCain endured in excruciating detail.
"For five-and-a-half years, this went on," Thompson told supporters at the convention. "John McCain's bones may have been broken, but his spirit never was. Now, being a POW certainly doesn't qualify anyone to be president, but it does reveal character."
McCain's character and his temperament have become an issue this election year. McCain's detractors charge that his ability to resist his Vietnamese captors so fiercely has a flip side — recklessness.
Former Vietnam POW Philip Butler appears in an ad, aired by an independent left-of-center group, attacking McCain.
"He was well-known as a very volatile guy, and he would blow up and go off like a Roman candle," Butler says in the ad. "John McCain is not somebody I would like to see with his finger near the red button."
McCain's Reputation In The Senate
Obama supporters like California Sen. Barbara Boxer are quick to quote the Republican senators that McCain has tangled with over the years.
"Just listen to what some of his Republican friends have said about him," Boxer said. "Thad Cochran, a Republican conservative senator from Mississippi, says the thought of John McCain in the White House sends cold chills down his spine."
Cochran is a member of the appropriations committee who clashed with McCain over pork barrel spending. But now he and McCain's other erstwhile Republican antagonists are supporting the Arizona senator and have nothing but praise.
McCain himself — often his own toughest critic — has written that he has a nasty temper and that it has caused him to make some serious mistakes.
But Mike Murphy, who ran McCain's presidential campaign in 2000, says the stories of McCain's temper are grossly exaggerated.
"I've seen a lot of politicians get mad. What's different about John McCain is when he's a little upset, he always gets upset up, not down," Murphy said.
Princeton University political scientist Fred Greenstein, who has written several books about personality and politics, said that he views McCain as a "kind of force of nature."
He says McCain's temperament had two distinct sides in the Senate.
"He could go off like a rocket launcher and spew profanity at somebody who crossed him or he thought was crossing him," he said. "But the other was that even the people he antagonized came to be comfortable working with him, and he has been a very effective legislative broker."
McCain can use a four letter word with a Republican colleague, but he's also willing to cross the aisle to cut deals with Democrats on big difficult issues like immigration and campaign finance. He made a bold gamble when he picked Alaska Gov. Sarah Palin to be his vice presidential running mate. He acted impulsively last week when he called for SEC Chairman Christopher Cox to be fired.
This Friday, when he debates Obama in Mississippi, voters will get a close look at a candidate who is at once scrappy, instinctive, down-to-earth and very tough.