The F.B.I. moved on Sunday to quickly complete an abbreviated investigation into allegations of sexual misconduct against Judge Brett M. Kavanaugh, even as Democrats demanded more information about the inquiry’s scope, warning that its apparent constraints could make it a “farce.”… Officials said the F.B.I.’s “limited” supplemental background check of Judge Kavanaugh could be finished by Monday morning. Set in motion late last week by three Senate Republicans, the inquiry was supposed to shed further light on accusations that Judge Kavanaugh engaged in sexual misconduct during his high school and college years and help resolve the fierce national debate over...