My mom is 76 and she proudly supports Obama (Hillary's unapologetic pro-war stance turned her off).
That did it for a lot of people.
All the post-mortems miss that point. No AUMF? No Obama. I doubt he even runs, and if he does there's no daylight for him to break out.
My 55 year old parents, both registered republicans (Dad's a libertarian at heart) are supporting Obama. My 84 year old grandma voted for Clinton in Colorado; she didn't feel she was getting enough substance from Obama at the time, but she's coming around.