Enough is enough, suggested Federal Deposit Insurance Corp. chairman Sheila Bair before an audience at the New America Foundation conference. “[W]e’re still very much behind the curve,” in modifying loans to prevent foreclosures, she said. “We need a fast-track, nationwide effort.” Critics say we can end the housing crisis without modifying troubled mortgages — call that a “myth,” Bair said. “Unnecessary foreclosures are a very serious threat to a housing recovery.”