One of the immutable rules when it comes to Washington politicians addressing important policy issues, is that they consistently ignore the law of unintended consequences.A recent example is the little noticed effort by congressional Democrats to change a key component of federal funding regulations for higher education called the “90/10 rule.”Under the rule, proprietary colleges and universities may derive no more than 90 percent of their revenues from federal student aid programs, with 10 percent coming from non-federal funding.Liberal activists who are determined to drive proprietary colleges out of business want to change the equation. They claim that student veterans...