Special interests may or may not prevail in the fight to end or limit the mortgage interest deduction, but it seems clear they’re ready for a good fight. In a recent article on CNNMoney, Jerry Howard, chief executive of the National Association of Home Builders (NAHB) called the effort an “attack on the middle class.” Moreover the National Association of Realtors (NAR), which spent $17.6 million on lobbying in 2010, says it will remain vigilant in opposing any plan that modifies or excludes the deductibility of mortgage interest. The Treasury Department estimates the cost of the deduction is sizable, an estimated $131 billion a year. Herein lies the problem with reducing the federal budget deficit, which economist Nouriel Roubini says neither party is serious about. “We’re kicking the can down the road,” Roubini tells CNBC in a separate article. “We’re not doing anything about the budget deficits.