On October 22 the Justice Department sued Alaska's Division of Elections in federal court, asking it to block or delay certification of the U.S. Senate race if Republican Sen. Dan Sullivan loses to Democrat Mary Peltola but would have won had the votes for a second candidate, Daniel J. Sullivan Jr. of Petersburg, gone to him. President Trump said he ordered the suit. The state's Department of Law answered that the suit "has no legal basis": the ballot labels the senator as the Republican incumbent, voters can rank both Sullivans, and probing voter intent would breach the secret ballot. Peltola's campaign and the Democratic Senatorial Campaign Committee moved to dismiss. Republican Sen. Lisa Murkowski said the department "should have never filed this lawsuit."

On October 28, AP reported that The New York Times had obtained texts in which Peltola campaign members discussed recruiting people named Dan Sullivan. Trump said Peltola and the other Sullivan "should be prosecuted"; Murkowski said Alaskans "deserve the honest truth." Peltola's campaign says it "has no involvement with either Sullivan campaign," the DSCC denies involvement, and Dan J. Sullivan has long denied any contact with Peltola's campaign. Legal experts told AP the report won't change the lawsuit. Election Day is November 3.