The Senate Banking Committee approved legislation Tuesday that would empower the Federal Housing Administration to provide relief to mortgage borrowers teetering on the brink of default. The House has already passed similar legislation. Only two months ago, mortgage aid was viewed as unlikely, but the odds now favor it becoming law. For this change of fortune, the legislation's chief sponsors, Sen. Chris Dodd of Connecticut and Rep. Barney Frank of Massachusetts, should thank one person in particular: Federal Reserve Chairman Ben Bernanke.