As the stalemate over debt talks dragged on Wednesday, Congress and the White House may have passed the point of no return in avoiding a U.S. government debt downgrade. If Uncle Sam loses his coveted AAA rating, the cost of borrowing goes up, the economy slows further and jobs get even tougher to find. With hopes fading for a broad deficit-cutting package of spending cuts and tax increases, the White House Wednesday signaled that President Barack Obama could support a short-term extension of the U.S. borrowing limit as long as it was part of a broader long-term deficit reduction deal....