...gets a New York Times bio:
By enlisting in the Marines, Jimmy seemed to be giving up his birthright. The Navy is, by reputation, the most aristocratic of the armed forces, the McCains among its most storied families. Now he would hold the lowest rank in a branch known for its grittiness. “The first time I heard he was going to be in the company, I couldn’t believe it,” said First Lt. Sam Bowlby, one of Lance Corporal McCain’s officers in Iraq.
The article also notes Senator McCain's reluctance to discuss his son's military career:
Mr. McCain did not speak publicly about whatever anxiety he may have felt about his son’s deployment
And Lance Corporal McCain's humility
Just before Jimmy’s departure, Mrs. McCain decided she had to see him one final time, according to Lieutenant Bowlby. With a few well-placed phone calls, she won permission to visit the Air Force base from which his unit would depart. When Lance Corporal McCain found out, he protested. No special favors, he said. Mrs. McCain stayed away.
You have to admire Lance Corporal McCain's willingness to serve his country, particularly in the toughest branch of service, especially given his family's background. Likewise, John McCain's reluctance to exploit his son's military career for political gain is equally deserving of respect and admiration.