Forty-two members of the Republican rank and file in the House sent a powerful message to their leaders last week when they joined with Democrats and voted to close an outrageous loophole that allows lenders to skim billions of dollars from loans that should be going to needy college students. At issue is a special category of student loans for which the government guarantees lenders a gargantuan return of 9.5 percent, even though the prevailing rate charged to students is lower than 3.5 percent. The loans, backed by tax-exempt bonds, were created in the 1980's, when interest rates were high,...