I'm sorry Tim, how long has McCain been in congress for?
But according to Tim, it was because of his wife 
quote:
In April 1979, McCain met Cindy Lou Hensley, a teacher from Phoenix, Arizona, whose father had founded a large beer distributorship. They began dating, and he urged his wife Carol to grant him a divorce, which she did in February 1980, with the uncontested divorce taking effect in April 1980....McCain and Hensley were married on May 17, 1980, ...McCain set his sights on becoming a Congressman because he was interested in current events, was ready for a new challenge, and had developed political ambitions during his time as Senate liaison. Living in Phoenix, he went to work for Hensley & Co., his new father-in-law Jim Hensley's large Anheuser-Busch beer distributorship. As Vice President of Public Relations at the distributorship, he gained political support among the local business community, meeting powerful figures such as banker Charles Keating, Jr., real estate developer Fife Symington III and newspaper publisher Darrow "Duke" Tully. In 1982, McCain ran as a Republican for an open seat in Arizona's 1st congressional district.
so, he started dating Cindy a year before he divorced Carol, married Cindy a month after the divorce. Went to work for her father as a VP of the company, then ran for congress two years later. So yeah, his military career is because his father and grandfather were admirals, and his post military career is because of his wife and her money.
those damn facts and their liberal bias