Probably the most liberal POTUS to serve in my lifetime. Sometimes I think Obama tries to go as Left as he can, while still remaining politically viable. He certainly, unlike Clinton, has done nothing to really upset his base, including doing nothing on entitlements, even though he won't increase taxes on the middle class to pay for it - just a 4% increase or so on those making over 250K, which gets you about one twelfth of the way to something that will pencil.
As I'm sure you're aware, the CBO would dispute you on the claim of yours I've bolded.
What has Obama done?
Five letters. PP-ACA.
PPACA does set the stage for cuts in Medicare but it doesn't actually do it. I think more cost sharing is needed but Ryan's plan is completely unacceptable. He is setting a cap on the government's expenditure per patient when in reality there needs to be a cap on the individual's expenditure after greater cost sharing. And if that requires a 90% tax rate on Millionaires (it doesn't of course) then so be it.