Raising the Medicare eligibility age isn't just a bad idea because squishy liberals like me think life should be easy for older people, or a bad idea because it's stupid fucking politics, it's a horrible idea because it will increase overall costs and mess up our already fucked up health care/health insurance markets more. Also, too, it will make life horrible for older people.
Mucking with Social Security is bad, mucking with the Medicare eligibility age is bad AND stupid. So it's probably the likeliest outcome then.