Lots of good thinking on this thread. Mind if I jump in?
100% free college education is nearly impossible in the United States given our current budget. There are about 12 million undergraduate students in the USA, and about 3.5 million graduate students. College costs range from a low of about $14,000 per year for in-state schools, up to about $47,000 for upper-end private schools. Let's take a broad average and say that the average student pays $20,000 per year for his/her education. Thus, 15,500,000 students x $20,000 per year = $310,000,000,000 per year.
For comparison, the total defense budget is about $510 billion per year, and current total education spending (federal and state) is $600 billion per year with $108 billion of that going to higher education. Thus, at the national level, this would increase the education budget by 50% and quadruple higher education spending. I don't know what other programs the government would cut, but that's a major shift in expenses.
Free college education would be nice if we could somehow pay for it.
Integral