Part of 'funding' college for everybody isn't just giving them the money to go to college, it's making sure public institutions have enough capacity to handle those students.
Instead of increasing grants, I think directly lowering tuition cost for public universities would force private universities to become more efficient and lower their tuition costs too... non-zero tuition makes for an interesting tension where public and private can compete in different ways (possibly making the system as a whole better than one with only, or mostly, free public colleges)
Instead of increasing grants, I think directly lowering tuition cost for public universities would force private universities to become more efficient and lower their tuition costs too... non-zero tuition makes for an interesting tension where public and private can compete in different ways (possibly making the system as a whole better than one with only, or mostly, free public colleges)