Catholic schools that serve the poor use fed Pell Grants to pay students way....and other forms of assistance for low income students.

Public state schools that might (getting congressional consensus is highly doubtful) carry students in family's with certain income limits (with fed assistance) is a fine idea, (these students might well be eligible for traditional assistance of some sort, as well). 

Families that just miss those income barriers and have a number of  kids to educate....are dipping into their pension funds, increasing their mortgages et al.....experiencing serious debt .....I have absolutely no sympathy for catholic educators bemoaning this proposal.....

To get an education, wherever possible....is incredibly important and should be actively promoted!

These catholic educators  perhaps don't appreciate the struggle that families country wide are experiencing sky rocketing tuition....