A Senate blue slip from 1917 for U.V. Whipple, a candidate for district judge for the southern district of Georgia, signed by Georgia Senator Thomas Hardwick, who wrote that "I object to this appointment—[Whipple] is personally offensive and objectionable to me, and I can not consent to the confirmation of the nominee."[1]
In the Senate, a blue slip is a slip on which the senators from the state of residence of a federal judicial nominee give an opinion on the nominee.