Honestly speaking, without these conditions, unless you end up top 1-5% in a tier 3 school AND want to work in the same area, future job prospect would be bad.
What is the position of a judge trainer, by the way?
Yes, green card helps.
The question is the costs v. benefits. If you don't mind taking a job that pays less than large firm rates, don't mind taking longer in job search, and don't mind taking cases like immigration, etc, there are opportunities to find jobs. And of course, if you are financially free, getting an education is a personally enriching experience.