He did more for his country than 99.9% of Americans. I think that's more important than not having been born on US soil. Plus he was born on American Base due to the fact that his father was on duty for his country.
Both McCain's grandfather and father were admirals in the United States Navy. McCain attended the United States Naval Academy and graduated in 1958. He was married in 1965. He became a naval aviator, flying attack aircraft from carriers. During the Vietnam War in 1967, he narrowly escaped death in the Forrestal fire. On his twenty-third bombing mission over North Vietnam later in 1967, he was shot down and badly injured. He then endured five and a half years as a prisoner of war, including periods of torture, before he was released following the Paris Peace Accords in 1973.
McCain escaped from his jet by climbing out of the cockpit, working himself to the nose of the jet, and jumping off its refueling probe onto the burning deck of the aircraft carrier. His flight suit caught on fire as he rolled through the flames but he was able to put it out. He went to help another pilot trying to escape the fire when the first bomb exploded; McCain was thrown backwards ten feet and struck in the legs and chest by shrapnel.
On October 26, 1967, McCain was flying as part of a 20-plane attack against a thermal power plant in central Hanoi, a heavily defended target area that had almost always been off-limits to U.S. raids. McCain's A-4E Skyhawk had its wing blown off by a Soviet-made SA-2 anti-aircraft missile while pulling up after dropping its bombs. McCain fractured both arms and a leg in being hit and ejecting from his plane[56] as it went into a vertical inverted spin. He nearly drowned after he parachuted into Truc Bach Lake in Hanoi. After he regained consciousness, a mob gathered around, spat on him, kicked him, and stripped him of his clothes. Others crushed his shoulder with the butt of a rifle and bayoneted him in his left foot and abdominal area; he was then transported to Hanoi's main Hoa Loa Prison, nicknamed the "Hanoi Hilton" by American POWs
Although McCain was badly wounded, his captors refused to give him medical care unless he gave them military information; they beat and interrogated him, but McCain only offered his name, rank, serial number, and date of birth. Soon thinking he was near death, McCain said he would give them more information if taken to the hospital, hoping he could then put them off once he was treated. A prison doctor came and said it was too late, as McCain was about to die anyway. Only when the North Vietnamese discovered that his father was a top admiral did they give him medical care and announce his capture. At this point, two days after McCain's plane went down, that event and his status as a POW made the front pages of The New York Times and The Washington Post. Interrogation and beatings resumed in the hospital; McCain gave his ship's name, squadron's name, and the attack's intended target. Further coerced to give the names of his squadron members, he supplied the names of the Green Bay Packers' offensive line.
Wow! Can't get any more American hero than that