can afford is correct

to be able to afford - sich leisten können

"Too many Americans still don't have health care they can afford." -
... immer noch keine Gesundheitsversorgung, die sie sich (auch) leisten können.

Oder : They can't afford the health care they need


... und : Who can help me to ...
:-)

... still don't have / can't find affordable health care.

I'd say

Re #4: If you're correcting then OP, then please:
Instead of ... und : Who can help me to ... 
it should be
"Who can help me translate..."

In Be, at least, both "help sb. do sth." and "help to" are correct and used.

I didn't know it was actually wrong in AE.

@0 Da 'they can afford' 'health care' näher bestimmt, bezieht sich das 'don't' auf den gesamten restlichen Satz:

Sie haben nicht (eine Krankenversicherung (die sie sich leisten können)). (dieser Satz ist natürlich kein richtiges Deutsch, soll nur die Bezüge klar machen)

#3
My first thought, too.
I wondered if the writer avoided it because of the phrase being used as a proper name (Affordable Healthcare Act).

The original sentence is badly expressed, and I agree with the improved English versions in #2 - '... can't afford the health care they need' - and #3.
Or the writer could have said '... don't have access to health care that they can afford'.