For Sen. Marco Rubio, student loan debt is not only a drag on the economy, but a personal issue. When he was sworn into office in January 2011, he owed more than $100,000 in student loans.
"So I'm keenly aware and sensitive to it," the 42-year-old Florida Republican told CNBC on Wednesday. "At one point in my life, it was the single-highest expenditure in our personal budget."
Seeking to help reduce student loan debt and provide student protections, Rubio, along with Rep. Tom Petri, R-Wis., will introduce a student loan bill on Wednesday. Rubio called for "income share agreements" between graduates and investment groups, in which graduates would make loan payments over a defined period of time in proportion to their income. So the more you make in a given month, the more you would pay back. The less you make, the less your monthly payment will be.
Read MoreRubio to offer bill on new education financing vehicles