He had ample opportunity to be. He deliberately threw the election to Zero.
You're assigning a degree of competence to McCain he doesn't actually possess. The only thing he's qualified for is holding down a government sinecure and posturing. When he's led any kind of successful legislative push, it's inevitably a cave to liberal interests. He's just an incompetent.
Dubya was incompetent, but less incompetent than McCain. Think about how Dubya almost lost to a couple of stiffs (Gore and Kerry). How could anyone think that a loser like McCain could defeat one of the greatest political talents since FDR - someone who secured the some of biggest popular vote margins ever in % terms, made huge strides in the liberal agenda despite GOP legislative majorities in 6 of his 8 years and emerged at the end of his tenure with a net positive poll rating? It's pretty amazing that the 2008 GOP primaries came down to two stiffs, Romney and McCain, both political zombies. When it got to that point, the writing was on the wall - even Hillary would probably have beaten either of them.
Some people..down deep don’t want to win.
Multiple crashed planes...getting involved in Keating Five....continually kissing up to the purported enemy...throwing the election....and now trying to work against his party’s POTUS. He seems to choose loser behavior.