What you're asking for is a solution in 10-15 years for a problem that's rearing it's head now. If you were to remove government backed loans, you would be locking a significant amount of the US population out of higher education. Without a higher educated workforce, where do you think workers for various jobs are going to come from if we decide to go full protectionist and reduce immigration potential?

Low cost universities don't just pop out of thin air and neither do the professors that staff them.