You are 100% guaranteed that she would elect someone whos first loyalty would be to Planned Parenthood. But with Rudy you at least have a chance that he would keep his promise to select Judges like Roberts and Alito. You would also have more political influence on him (same goes for any of the Republican nominees), where you will never ever have a seat at Hillarys table.
What you are doing by helping her get elected is loosing any minute chance of a voice at the Oval Office.
Let’s face it Souter and Stevens vote in lockstep with Ginsburg. They were nominated by Republicans - add O’Connor and Kennedy, fellow travelers. Won’t be fooled again.