End federal subsidies and loans. For every dollar a school accepts of federal funds they are required to maintain a certain percentage of private funding. Since a very big portion of this funding ends up coming from federal sources, the end result is they are constantly required to jack up tuition prices to meet the minimal private funding level. Once this is changed so many other issues will begin solving themselves.
Too many people who don't belong in college are burning vast resources to get degrees in underwater lesbian basket weaving and then doing nothing with the degree and ending up in massive debt. The current educational system is one big lesson in inflation.
I really don't think the federal loan program is that big of a factor, and isn't it a profitable program overall anyway? The loans aren't that big, and even if the student gets buried in private loans they can't make payments on the government loans will still get paid. I think the max an undergrad student can get in subsidized loans is $5k a year for 4 years and they have to be enrolled as a full time student. If the kid ends up making even 10% more over the period of an average life with an average income, that's a great return when you add up all the extra income tax.