"On Nov. 21, two weeks after Nixon’s reelection, Blackmun sent around revised drafts of the majority opinions. The Roe opinion said that for the first three months of a pregnancy, states must “leave the abortion decision to the best medical judgment of the pregnant woman’s attending physician.” In a memo to his colleagues, however, he voiced uncertainty. “This has proved for me to be both difficult and elusive.... You will observe that I have concluded that the end of the first trimester is critical,” he wrote, referring to a cutoff date for permitting abortions. “This is arbitrary, but perhaps any other selected point, such as quickening or viability, is equally arbitrary.” The first trimester is the first three months of a pregnancy. Brennan, Marshall and Powell wrote back to say that allowing abortions until “viability” -- when a fetus has developed enough to live outside the womb -- at six months made more sense. Douglas disagreed. “I favor the first trimester, rather than viability,” he said. He was outvoted, however, and Blackmun said he would revise the opinion over the Christmas holidays. In his final draft, states were told they could not restrict abortions through the second trimester."