Lawmakers from three states with relatively high housing costs are pushing for a bill that would boost loan limits for Fannie Mae, Freddie Mac, and the Federal Home Loan Banks – although some trade groups are gearing up for a fight. H.R. 3507, the “Improving Homeownership Opportunities in High-Cost States Act,” was introduced in the House by California Democrat Brad Sherman late last month and already has 20 cosponsors. The legislators all hail from