She will run whatever her health situation is. Why? She is addicted to power. And there are drugs that can keep her looking energetic and alert. Even in the early 60s, JFK was a mess physically, but drugs kept him going—the Public never suspected a thing.
But I agree with Matalin—she will be challenged and her nomination is not assured. Hillary is a flawed candidate at best. I am still amazed that Obama managed to beat her in 2008. This is her last shot and she will fight for it with all her might. She needs to prove to herself that she can do what Bill did.
The best instance for Palin is a Hillary run.
But JFK was only in his 40's, Hillary will be 69 years old in 2016, considerably older.
I don't think she has the physical stamina to maintain a Presidential campaign.
She also has thousands of "friends" and hangers on who are also addicted to Federal power and are pushing her to run. So the decision is not just hers. If Hillary becomes president these friends and associates get high FedGov appointments and crony capitalist deals.