Hiring is often a big filtering process. Get all the resumes and go into a throw-away frenzy. Keep 10% of them at most. Felons very likely to end up in the throwaway pile. Even worse I suppose if a corporate HR department is pre-filtering resumes.
My standard advice for ex-cons is to see if they can start and run a small business. Some businesses require background checks to be able to work in (government contracting, anything to do with schools, etc) but some don't have customers who check backgrounds (small IT repair shops). Unfortunately, this requires some capital to get going and also require some ambition and willingness to fail to try starting a business.