A mass mortgage refi solution is getting support from both sides of the political aisle. And it wouldn't cost taxpayers a dime.

FORTUNE -- Main Street taxpayers have bailed out Wall Street. Now it's time for Wall Street to return the favor by footing the bill to help millions of honorable Main Street borrowers pay lower interest rates on their mortgages, something that should have happened years ago. Wall Street giving back to Main Street -- imagine that!

We're not talking about anything risky to taxpayers, or a magic fix for the housing market. We're talking about picking some low-hanging fruit by doing one simple thing: helping borrowers who are current on their payments refinance high-interest mortgages on which taxpayers are already at risk. That would help...