Thomas Sowell's spending cut plan targets Reverse Robin-Hoods: "My plan would start by cutting off all government transfer payments to billionaires." He mentions farm subsidies and "green" energy gravy.
Also, "Social Security and Medicare are supposed to be among the most difficult programs to cut without ruinous political consequences. However, it is not necessary to attack all the spending on these programs in order to make big savings. Instead of attacking these programs as a whole, what is far more vulnerable is the compulsory aspect of these programs." Allow people to opt out.
If one buys the idea that Medicare benefits are generous compared to what recipients paid in in taxes, it's not clear that so many people would choose to opt out of what is, for the recipients, a good deal. And the less good the deal becomes, the less money the government saves when people opt out. The best case for allowing people to opt out may be less related to the federal budget and more related to individual freedom and choice.