Alhough I have my doubts about whether the bill in toto will reduce costs given the lack of statutory control over insurance premiums and lack of drug reimportation, the idea that it's cheaper to "give" uninsured people insurance than have them rely on emergency care or indigent services makes sense.

If someone doesn't have insurance they don't get preventative medicine/checkups or routine care where things can be diagosed and corrected at a much earlier stage. Usually they wait until symptoms can no longer be ignored. With things like cancer, diabetes, hypertension, etc, this can be pretty expensive to treat-that is of course if the person is lucky enough to be treated.