DALLAS, Oct. 4 - By 1979, Harriet E. Miers, then in her mid-30's, had accomplished what some people take a lifetime to achieve. She was a partner at Locke Purnell Boren Laney & Neely, one of the most prestigious law firms in the South, with an office on the 35th floor of the Republic National Bank Tower in downtown Dallas. But she still felt something was missing in her life, and it was after a series of long discussions - rambling conversations about family and religion and other matters that typically stretched from early evening into the night - with...