Employee Rights

Under an "At Will" contract in the State of California an employee can be terminated with no notice, no pay in lieu and no reason given for the termination, no matter how long they've worked for the company. This has happened to me three times now. I believe that this is ethically wrong. An employee has the right to know why they are being terminated and to be given an opportunity to defend themselves or put right any grievances that the employer may have against them. I had no feedback at all from my employer as to why I was being terminated, and this is very detrimental to my future employment prospects, as if I don't know what's wrong I can't improve my performance. Plus I am emotionally traumatized by these events, and with the lack of information it's hard to move on. I would like the State of California (and other states if appropriate) to enact new laws protecting employee rights, stating that an employee has the right to have:
1. A valid reason for their termination.
2. A chance to petition the employer for reconsideration.
3. Written warning before termination, and the opportunity to put right any performance-related issues before termination is considered.