Steven Hayward's follow-up Reagan profile, The Age of Reagan: The Conservative Counterrevolution (1980 - 1989) is available August 25. 

The first profile covered 1964 - 1980 and is a highly readable story of the face of Conservatism in the United States.  In my mind, only Martin Anderson's Revolution does a better job of capturing the confluence of events that led to the Reagan administration.  From the first Age, a story about a 1979 conversation between Reagan and national security adviser, Richard Allen:

"'Who is he?'  'Who is who?' Allen replied.  'Who is this Jeane Kirkpatrick (author of Commentary essay Dictatorships and Double Standards)?'  'Well first, he's a she.'  Reagan wrote to Kirkpatrick in December to praise the article.  Your article, Reagan wrote 'had a great impact on me. . .Your approach is so different from ordinary analyses of policy matters that I found myself reexamining a number of the premises and views which have governed my own thinking in recent years."

The two met and another piece of the puzzle was put in place.