I think it was Bill Clinton who said if you liked what happened in the 60's you are probably a Democrat and if you didn't you are probably a Republican, or something to that effect.  It might be better to say, if you care about the 60's you are probably out of touch.  
The last several elections people have tried to define themselves by what they did in the 60's.  John Kerry tried to play up his service record in Viet Nam, and now John McCain is doing the same thing.  A good question for John McCain might be "how has being a POW prepared you for the oval office?"   
The country has changed since the 60's but some people have not, they are still arguing about the Viet Nam war and whether or not the sacrifices made by the country were worth it.  No wonder McCain is not interested in the price of gas in 2008 as in 68 I am sure it was affordable, but Viet Nam now that is an issue, at least in the mind of John McCain it is an important issue; in fact it seems to be the only issue. 
Any debt that the country owed to John McCain for his service has long since been paid, (letting him skate on the Keating five scandal is more than enough payment).  John McCain is certainly not owed the presidency for a sacrifice he made many years ago.  It seems that an entire generation of people define themselves by what they stood for in the 60's and it is starting to seem like most of them are uniquely unqualified to lead in the present.