I'm thinking that if abortion was not as legal is it is, there are probably millions of people more in the US able to keep Social Security going. Plus, there would be less illegal aliens working in the US who send their earnings to Mexico. Instead, there would be US citizens working those jobs, spending or saving in the US.
Medicare D should be repealed, then Medicare A/B, then Social Security, in that order. Every other budget item don't do much for the debt/deficit.