The suggestion of building up some positive cred through volunteer work is a good one I think. A part-time volunteer position with a non-profit can turn into a full-time job.
I also wanted to second (third/fourth?) the suggestion of trying to get hired by a small business. They're less likely to run background checks, especially if it's an "alternative" business. For example, "green" businesses that install solar, design/install environmentally-friendly landscaping or pools, water gardens etc.; bike repair shops; restaurants, esp. the hippie/punk ones; tech start-ups (you don't necessarily need to be an IT person or an engineer), etc.
I've run a few small companies and it was part of the philosophy to give back to the community, which included hiring interns/employees who were "at-risk" youth and/or recovering addicts and/or people like you who had criminal records and would otherwise be SOL when it came to getting a decent job. A decent job meaning one that wasn't entirely soul-sucking and that offered the opportunity to learn skills that would give a person the chance for a career.
Anyway… this isn't about what a wonderful, big-hearted saint I am, because I'm not. I'm an asshole like everyone else or worse in a lot of ways, but the point is that there are people out there like me who are willing to give people a second or third chance in life. You just have to find them.
Find the work training programs in non-profits in your city and get yourself involved with a few of them. Sometimes we'd hire someone through word-of-mouth, like "my cousin's cousin's boy just got out and needs a job"… but we also contacted non-profits in our neighborhood to find out who had work programs and people who needed work.
Check out craigslist. Non-profits are all over craigslist looking for people to do stuff for them for very little money. Hey it sucks but you're probably going to have to do some shit work here and there to build a decent job record. It'll work out. You'll find something. Once you find it, build on it.
You're an intense person, and with persistence, you can probably a position that will let you channel some of your energy into something that pays and is legit. Another good thing about small companies is that there's flexibility to do a lot of different things and room to move up. That's great if you get bored quick, and if you like having something you can call your own: your own project, your own team, a particular set of clients who prefer to do work with you, whatever. Power: feels good, man.
Wishing you the best of luck.
ps. Maybe work on that pardon in the mean time. Even if you could get 36 felonies expunged, think of the lawyers' fees. Fuck that noise.