Okay. If he wants to, your boss can, in your at-will state, fire you for anything. Just because he doesn't like the color of your socks. Whatever. But what a couple of your co-workers claim you said in a private conversation about the working conditions, about the work, about the boss, etc, through the years or last Tuesday IS NOT a valid work related misconduct reason to terminate you in my humble opinion.
I would need to hear more and get more details about the situation and about the exact reason you were given for your termination before calling it that. It was very very lousy poor judgment on your part to make a public display of bad mouthing your boss to co workers, particularly new co workers. It is something you should never have done, you should have worked your frustrations with the boss and the job out in more productive ways. And of course, you should have stopped doing it immediately when the situation "got out of hand" back when that particular former co worker you mentioned was at your little gathering. You should've a long time ago quit being the chief mouth and pot stirrer in your workforce, and just been doing your job to the best of your ability and keeping your mouth shut. It's a wonder you haven't been told on a long time before now.
That said, it's pretty much a case of "they say/he said...." which is probably not going to be particularly much work related as much as it's going to be personally insulting to the boss. And is there a boss out there who's silly enough to think his employees don't bad mouth him off the job, or that he can control what they say and do off the job?
Perhaps if they could produce video of you saying mean things about the boss and the workplace, your boss would have a fairly good reason to be a little perturbed with you. But obviously this has been going on for quite a while. Is HE, your boss the one who said that he thinks perhaps the turnover rate may be due to your comments? Or is this just office scuttlebutt? Did he give you specific warning that you will be fired if you do it again? How can you be "about to be fired?" Explain your situation. If he's said, "Don't ever do it again!" then don't. Problem solved.
The example that was quoted regarding a firing that was determined to be actual misconduct that resulted in denial of unemployment does not really seem relevant to this particular situation from what I am hearing here. That was a case where a worker on the worksite first of all, had been warned before about doing this particular thing, in other words he knew what he was not supposed to do. And then he actually gave orders/information/suggestions, encouraging other workers to disregard the other person's instructions, supervision, etc., in direct conflict with what the boss had instructed the workers to do. This was misconduct. This was encouraging other workers to disobey a direct instruction by the supervisor, after direct warnings to change his behavior in this regard. This was pretty much insubordination /actual work related misconduct.
Saying, "Oh, by the way, you new employees over at the old workhouse we call a job, you need to know our boss is a real Scrooge, nobody gets a raise, ever, and don't ever tell him his shoe is untied, he'll go nuts and yell at you! Yeah, he threw a staple gun at one of the guys last year!" is not insubordination. Especially when it is not said at the workplace.
Frankly, I cannot imagine hearing this as a new employee and going on and quitting the job, myself. I think most people will go on and try to find out for sure themselves what the job and the boss are like, regardless of what you have to say about it, because as someone said, jobs are hard to find, jobs are important to keep. I'm not at all sure the reason for your company's high turnover is anything you've said or done through the years.
You'll just have to see what happens. Above all, keep your mouth shut, keep your head down, stop discussing this whole thing with your co workers, on or off the job.
The boss may fire you for saying it, or doing it, he has the right to do so. You cannot sue him. This would not be wrongful termination or anything like it.
But by all means, if you are fired, FILE AT ONCE FOR UNEMPLOYMENT BENEFITS. No one who is terminated, even if they do not think they will be approved, or have been told they may not be approved on this website or any other, should hesitate to file for benefits, and go through the process of applying for unemployment insurance. It costs nothing to file. You have a right to do so and get a determination of eligibility.
And the circumstances may be such that you can be approved. We don't hear all the facts here by any means. While your employer is free to terminate you for just about any reason, in order to keep you from drawing benefits, they must show that they had a valid job related misconduct reason to terminate you. That you knew your actions would result in termination, and you persisted in doing them. It must be either misconduct after you have been warned about the misconduct behavior, or it had to be something so wrong, so extreme, that doing it even once was reasonably going to get you fired, and you knew it. For example, the former employee who got in a fist fight with his employer? No warnings necessary, that was gross misconduct.
But lets face it. There are a lot of people who get together and talk smack about their job. The new employees tend to get the big stories about how bad it is, how eccentric the boss is, how bad the work load can get. You were out of line, exhibiting poor judgment to start and continue this, but don't let it stop you from filing for benefits IF you are in fact, fired.
