To attack medicare now is like Goldwater advocating to privatize TVA in 1964. It was a good enough idea, but a large stationary target for the demagogues. Likewise Medicare, which takes care of almost everyone's grandparents, most of our parents, and many of us.
Remember grandma in a wheel chair being pushed off a cliff? That is the image you need to counter, and you won't do it by offering some erudite sharp pencil accounting and abstract treatise on limited government.
Find and promulgate a good alternative-- please--but don't think for a nanosecond that any politician up for election will want to dump Medicare.
The ONLY real, valid alternative in life is freedom. Freedom is at the heart of this and most issues these days. What you say, which is probably true, is that your run-of-the-mill politician sees no political future in freedom. Of course that makes sense since political freedom is the absence of government and government coercion.
Tremendously valuable and easily lost individual freedom or liberty is being drowned out by the deafening drum beats and bull horns of the Leftist MSM, government schools, government press corps, and politicians grasping for fame, fortune (your money) and power (at the expense of your freedom). The illusion of government-provided security and "equality" seems now to many if not most to be worth the price of individual freedom.
There are very few times in the history of man that a society has lived free for any length of time. Almost all of the history of man is a story of misery and oppression under tyranny. America for about 125 years or so until around 1900, is one such rare example. What we are seeing now is the throes individual freedom being smothered by the relentless march of oppression and tyranny in the temporary veneer of "care" and "compassion and "equality."
The free market economy is freedom in action and is the only source of true wealth as it was for America in the 1800's. I and certain others will always be a freedom fighters even if many or most choose the road to serfdom and darkness as Hayek put it.