What planet are you living on? No they most certainly have not!
Obama wants to raid Medicare to pay for Obamacare! To the tune of about $600 billion over 10 years.
Ryan wants to reform the program, so that seniors over 55 see no change whatsoever, and the system can be put back on the road to financial solvency for future generations.
If we were talking about a patient on an operating table (Medicare) and the tale of two surgeons (Ryan and Obama)... Ryan wants to perform a triple bypass, thus allowing the patient to live on for many more years, by fixing the problem. Obama wants to extract the fillings in the patients teeth and check their pockets for cash!