Having your hours cut very significantly, and you being the only one this is happening to, and it very apparently being a sort of try to get rid of you move, you very likely could quit your job and file for unemployment benefits and might get approved. But filing for partial benefits would mean more money, at least until the employer does something else, either fires you or gives you more hours.
How many hours did you usually work in the last 6 years? Were all the employees hours cut lately due to the economy, especially the other part timer? Have they now been restored to what they used to be?
If I were you, I might consider talking to the EEOC commission, because it's pretty obvious the manager is trying to force a quit here. And hiring kids to take your place. This looks suspiciously like "ageism" to me. But anything related to this would not be an immediate thing, probably should only be done if he actually fires you. Even if it's not determined to be a valid case, maybe it'll scare him.
The thing about unemployment is that you could file for partial benefits, IF your gross wages in a calendar week are less than the amount you could be drawing a week in unemployment.(Doesn't matter if you're actually paid monthly or bi-weekly) To find this out, you'd have to go on and file a claim for unemployment.
I think you should do this, get a claim set up, know how much you can draw a week. The question they will ask the employer is, "Is this person working all the hours he has been given, or that you have available for him?" If they don't like your filing, they always have the option of increasing your hours. Or firing you outright, which will just about guarantee that you get unemployment approved.
Whatever happens, do file for your benefits if you decide to quit, or if the employer takes you off the schedule all together. But do not say, "I quit!" because your hours are cut until you've tried filing a claim for partial benefits.
Start right away, get it on record, and then let the chips fall where they may. If you get the claim set up, then any week that you make less than you could draw that week, you can suppliment your income by receiving some unemployment and the wages you made working.
Though unemployment is less than almost anyone could make working full time, and it does end eventually, it is certainly better than just the very part time thing you're doing right now, not by your own choice.
