Clark's primary thematic focus in Before I Say Good-bye. As she reveals in an interview with Claire E. White, "I write about very nice people whose lives are invaded. They're not screeching at each other at the breakfast table. Something happens that cuts across their lives. They have to respond to it and solve the problem. . . . It's not American Beauty; it's not that kind of relationship at all. I choose to write about people whose trouble comes from the outside, not the inside." In other words, it is not psychological, but social disruption that intrigues Clark. As the novel describes the attack on Nell's life by her husband, it correlates this abuse to larger social problems: women's victimization by men and the threat to the professional classes by the refractory rabble. Before I Say Good-bye presents us with an insular world of privilege, where a woman may be able to take over the patriarch's place as its head representative, but where other kinds of social mobility are thwarted. Adam attempts to enter this world of privilege by marrying Nell and exploiting her high-profile connections to find himself a position at a renowned architectural firm; however, he remains a perpetual outsider. Nell's grandfather, Mac, disapproves of him from the beginning. Although he never clearly outlines his grounds for disapproval, he reveals a prejudice against his lowly background when he notes the incongruity between Adam's appearance and reality: "You're from a one-horse town in North Dakota, but you look and sound like a preppie from Yale." Alluding continually to Adam's disadvantaged socioeconomic background in order to justify its ultimate assessment of him as a sociopath, the novel implicitly suggests that Adam's upbringing in a hick town and a "broken home" explains how he becomes a threat both to women and the professional classes. As his past employer explains about him, "Adam Cauliff believed absolutely that he had a right to anything he wanted, be it a woman or a simple possession . . . [he] has a serious personality disorder and is probably a full-fledged sociopath. . . . He appears to have a complete disregard for, and to be in conflict with, the normal social code by which most people conduct their lives." Once Adam is killed, Dan conveniently assumes Adam's former role as Nell's love interest. A more suitable match for Nell, in terms of both background and pedigree, his character symbolizes the reinstatement of the social order as the novel defines it: one where women can succeed as well as men while still maintaining the trappings of femininity and one where politicians marry doctors, not small-town hicks.

Linked to this fear of invasion is the desire to retain power. Informing the two key power struggles in the novel are the social divisions of class, gender, and age. The first contest of power is between Adam and Mac. Adam's incursion into Manhattan's professional elite threatens class boundaries. Mac repudiates him on the grounds of social inferiority, while Adam resents his prejudice, observing to Nell, "I was never good enough for you, never good enough to mix with your precious grandfather's cronies." Siding with Mac, the novel condemns Adam as a sociopath and kills him off in the end; it apparently supports the class distinctions that Mac fights to uphold. The second, and more complex, contest of power occurs between Mac and Nell. Nell's attempt to enter the political sphere that her grandfather once dominated is fraught with tension. Reluctant to lose his position as Manhattan's reigning patriarch, he proves to be a domineering, though benevolent, mentor to Nell. "They fight constantly," Clark reveals in her interview...