The Federal Home Loan Mortgage Corp. — Freddie Mac — lost nearly $26 billion last year, it was revealed last month. That makes a total of nearly $80 billion in losses for the mortgage company. Freddie Mac and its cousin Fannie Mae, private companies enjoying government backing for many years, are responsible in some measure for the so-called real estate meltdown. At the urging of Congress, the two companies backed millions of shaky borrowers, many of whom defaulted on their mortgage loans. The defaults are continuing. Freddie Mac officials said about 4 percent of the entity’s borrowers are at least three months behind on their mortgage payments. Neither Congress nor some of the big lenders have done much to encourage more responsible borrowing. Why should they? Taxpayers always can be tapped to make up for losses on foreclosures. By fall 2011, it is expected that taxpayers will have covered $188 billion in losses by Fannie Mae and Freddie Mac.