It's sorta like a "triage" metaphor. Who is the more salvageable, who is the less "contagious", who is less likely to "throw me under the bus", who is the lesser liar; who is less likely to harm my daughter; who is a better influence on my son; who would you more trust with "the codes"; who seems to know what they are talking about; who has been recorded as having and being proud of sexual abuse; who knows the date of the election?