The former congresswoman is the latest top-tier recruit for Democrats, who face a difficult Senate map this year as they try to retake control of the chamber.
A Republican-led effort to repeal Alaska’s voting system has gathered enough signatures to put the question before voters again.
Alaska's appointed attorney general on Friday filed a friends of the court brief in a case before the U.S. Supreme Court involving whether absentee ballots that arrive after Election Day can be counted.