couple of thoughts
a) I think the cost of people is finally coming home. We breed more and more people for fewer and fewer jobs. Between the illegals, out-sourcing, and 'taxed to death' there just isn't much left anymore. The unemployment isn't as bad as a lot of other nations though, so that is relative.
b) we have, ever since FDR began the entitlement mentality, increased the number of parasites and leeches. Over half the population now gets their paychecks from the government. This includes your welfare recipients. If we have another depression like crash with massive unemployment, the gubbermint just does not have enuf money.
You can all produce your own scenario, but then, this may be exactly what some folk want: the excuse to remove our 'rights', suspend the Constitution and bill of rights... However this will be done to everyone since we have to be democratic about it. (Government will be unable or unwilling to protect people from the masses of the entitlement minded mobs of welfare, hispanics, blacks, and whatever else is on the dole.)