How can the justice system be altered to not favor the wealthy?

Put simply, if I’m very rich and commit crime and I have a better chance of avoiding a harsher sentence than one who can’t afford substantial legal fees. Similarly, if I would like to prosecute a corporation for some injustice (think Wal-Mart or Monsanto), I can’t sustain a protracted case and they know they can wear me out.

What changes could be made to our justice system to level the playing field?