Alaska is the only Senate race yet to be called. Democratic challenger Mary Peltola is narrowly leading Republican incumbent Dan Sullivan with about 86% of votes counted. Alaska uses ranked-choice voting, a system where voters choose not only their top candidate, but can also indicate an order of preference for remaining candidates on the ballot. If no candidate wins a majority as the top choice, then second-choice votes are added to the totals and so on until there is a winner.

Rob Richie, president and founder of Expand Democracy and a senior adviser with FairVote, explains how ranked-choice voting has shaped the Alaska race and how it is “a system that promotes [candidates] reaching out, engaging, and, for voters, a lot of freedom.”

Richie adds that Peltola is “heavily favored to win at this point.”