He is the author of “Celebrity-in-Chief: How Show Business Took Over the White House” and “Presidential Debates: 50 Years of High-Risk TV.” Ostensibly a transaction between the president and Congress, the modern State of the Union message has morphed into something quite different: a big-ticket media extravaganza that holds only minimal relevance to executive-legislative relations. In his 1982 State of the Union, President Ronald Reagan invited Lenny Skutnik, who was the first in what has become a tradition of notable people sitting with the first lady during the speech.