"Tell the FBI that the kidnappers should pick out a judge that Nixon wants back"

This quote by William O. Douglas is most likely referring to the Watergate scandal of the early 1970s. At the time, President Richard Nixon was facing impeachment proceedings due to his participation in the scandal. Douglas was most likely suggesting that the FBI ought to inform the abductors to choose a judge that Nixon would be comfy with, as this would be useful to Nixon's case. This might be analyzed as Douglas trying to secure Nixon from additional legal effects, as the judge picked might be sympathetic to Nixon's scenario. Ultimately, this quote reflects Douglas' viewpoint that Nixon ought to be given a fair trial, no matter the allegations versus him.