structural:expansion
Drafting the opinion

Blackmun continued to work on his opinions in both cases over the summer recess, even though there was no guarantee that he would be assigned to write them again. Over the recess, he spent a week researching the history of abortion at the Mayo Clinic in Minnesota, where he had worked in the 1950s. He talked daily on the phone with George Frampton, his 28-year-old law clerk who stayed behind in Washington, D.C. Frampton researched the history of abortion using a book authored by Lawrence Lader, the founding chairman of what is now called NARAL Pro-Choice America. Blackmun's papers made available since his death contain at least seven citations for Lader's 1966 book, Abortion. Chapter 16 of his book, "A Blueprint for Changing U.S. Abortion Laws" predicted that if abortion were to be legalized, "the possibility of community opposition is slight". Lader also predicted that "If such a theoretical case was carried to a high court, perhaps even the U.S. Supreme Court, and the judges confirmed a broad interpretation of the meaning of a threat to life, undoubtedly a landmark in abortion decisions would be reached."