His tendency to vacillate on the issues appears to be his inability to handle defeat or the fact that he can't win them all. His blaming his Secret Service agent for his tumble while snow boarding is a prime example of this
"From everything I have learned about John Kerry in the past year by reading testimonials by people who know him, those he served with, his Military records, and looking at his Senate record, it's reasonable to conclude that John Kerry has a serious problem dealing with those in authority."
I think it's simpler than this. He's a liar and a pompous ass.