We've seen what happens when Republican governors refuse to go along with new federal spending programs. Almost half the states have rejected Medicaid expansion funds under Obamacare. Already, Republican Governor Scott Walker of Wisconsin says he would not sign up for Clinton's college plan.

For the record, Wisconsin has some of the most expensive community colleges in the country and ranks 27th overall in affordability. But nearly every state has a college-cost challenge. Higher education is less affordable now than it was in 2008, says a recent report, "College Affordability Diagnosis: National Report."

The average in-state tuition for four-year state schools is $9,410, while the average tuition at private colleges is $32,405. The rough rule of thumb is to double those amounts -- to include room, board, fees, books, travel -- to get the all-in, full-year cost. The median U.S. household income is about $55,000. It's clear why typical American families can't afford to send their kids to college without taking on debt.

The affordability study contains some damning statistics. For example, for every new federal government student-aid dollar available, colleges have raised tuition -- 60 cents on the dollar, according to a New York Fed estimate. In other words, the more aid that is available, the more tuition goes up.