GREENSBORO, N.C. — When former Senator John Edwards, a man who reached for the presidency while scrambling to hide a pregnant mistress, heard on Thursday that a federal jury would not convict him on the six corruption charges he faced, he fell back in his chair and closed his eyes. For just a moment, the man whose most intimate sexual details, lies and bare political ambition had been aired for nearly six weeks in a federal trial, looked as if he might cry. Yes, he said as he left the courtroom, he had sinned. “I did an awful, awful lot...