It would be political suicide for any politician to threaten the social security Ponzi scheme and to cut Medicare.
Any time any politician who can clearly see the state that Social Security is in right now and says that we need to fix it, is crucified by the head-stuck-in-the-sand liberals. Liberals just close their eyes and pretend that the government has an unlimited supply of money to do whatever they want to do.
Social Security is losing money. It was a Ponzi scheme invented to give the government a ton of cash at a time when the average life expectancy was 40 years. But then technology began extending life. Politicians, on both sides, still just cannot keep their hands out of Social Security. It was about 15 years ago when it started paying out more than it took in. At some point the entire house of cards will come crashing down because when anyone says anything about fixing, people like you start blaming Republicans of wanting to destroy it. It is perhaps the single worst way to invest money for retirement. If we were free to take that money and invest it somewhere else we were be far better off, but the politicians wouldn't have their cash cow to rob from.