A major task for the next Congress will be rewriting the laws governing Fannie Mae and Freddie Mac, and House Republicans have now won a seat at that table. Which makes it all the more important that their seat not be occupied by Members who were once powerful defenders of the toxic mortgage twins. These days, everyone—even Barney Frank—claims to want to reform Fannie and Freddie. Most Republicans now sound like these columns did for more than a decade, assailing the companies for their systemic risk to the financial system after taxpayers have had to put up $150 billion…