True! But in STEM fields the money to pay for PhD students (tuition, stipends, fees, insurance, etc.) almost always ultimately comes from the Federal government

True! But in STEM fields the money to pay for PhD students (tuition, stipends, fees, insurance, etc.) almost always ultimately comes from the Federal government in one form or another. Typically, it'll be paid for out of one of their advisor's grants (which usually are from a Federal source), or sometimes from a training grant of some kind (e.g. an NIH T32 or some such, which is also from a Federal source).