How about this idea:
In order to receive welfare, current (American) citizens on welfare will be required to work these "jobs Americans dont want" in order to receive welfare.
Of course, the welfare pay-out would be less since the recipients will have a low income (5.15/hr).
That should take care of it.
Your argument is now blown out of the water.
Try again -
If they were working these jobs they wouldn't need welfare then, right? The fact that they aren't means that they don't want to and no amount of government force isn't going to make them.
Speaking of water....UH, AHEM...