The Trump Administration is scavenging for ideas to lower costs for home-buyers. One idea being considered is to ease credit checks for loans backed by Fannie Mae and Freddie Mac—that is, backed by taxpayers. Americans saw a version of this policy two decades ago, and it didn’t end well. Mortgage rates have dropped in the last year, but many Americans still can’t afford to buy a home. Enter the Mortgage Bankers Association, which is lobbying the Administration to let lenders underwrite mortgages based on a single credit report. The outfit says this would reduce borrower costs. Maybe, but taxpayers may pay a bigger price later if this results in more defaults. The Federal Housing Finance Agency currently requires lenders to pull three credit reports. …The real reason lenders want to eliminate the tri-merge requirement is so they can make more loans to borrowers with poor credit. [to access the full story a WSJ subscription is required]