The paul ryan plan does an excellent job of reducing medicare and medicaid spending.
I strongly encourage Romney to campaign heavily on the Paul Ryan plan, which cuts medicare and medicaid spending by decree (we will cut x%, and cut everything else by 80%) without explaining how that would happen or would translate into changes policies. But if Romney wants to lose the one age group he's guaranteed to win against Obama, running on cutting Medicare would be helpful, which is why he's not going to do it.
Certainly Medicare and Medicaid are programs where youngs and poors have to pay more and more tax while the the far wealthier Tories collect more and more benefits.
One very smart commentator correctly described Medicare as a transfer program from black males to white females.
It's very prudent for Romney to correctly strike a balance where he can compete for the votes of non-basement dwelling 25 year olds while still retaining a landslide majority of seniors.
I would wager that Obama does very well among the under 30 year olds with no children who have a job and what not. Think the existing CA 53.