Re: @Don Jefe
The 'with cause' clause varies wildly between States as well. Where our main office is located, terminating someone 'without cause' may result in an unemployment benefits hearing where, depending on the outcome, I might be on the hook for increased unemployment insurance payments, but as long as I don't state the reason for their firing as being for one of the few prohibited reasons the (ex)employee has no legal recourse. Even if they did press ahead with a suit, 99.9% of judges won't hear those cases and as a result most capable lawyers won't take them.
Insubordination is a really common out for employers too. It is considered a zero tolerance, zero recourse offense that also does not qualify the employee for unemployment benefits or post employment insurance extension. Got a smart mouth employee with a bad attitude or one who can't show up on time or doesn't follow stated policy (disrupting company culture, personal appearance or hygiene, dress code, refrigerator use rules): Insubordination. You don't even have to state specifics to the unemployment office. Just "Insubordination, refusal to comply with stated policy", and you're golden. So you write company policy in an incredibly vague and Byzantine way (there are law specialists just for that), give them a copy and have them sign a policy receipt and acceptance form and that's all sorted.
All that being said, those laws always lean toward the employer because they are supposed to be there to keep wholly undesirable bad hires from terrorizing your business internally. But far, far, too many companies use them to be complete assholes. The US view that law can't be abused, only misapplied, allows dishonest or immoral moose dicks to treat staff like poorly paid indentured servants. It really sucks and with small/small medium sized companies word generally gets out and their business suffers (and hopefully dies). With larger companies though it can be a part of the culture and it is really, really shitty.