 A month after Xenophon's announcement, Tarzia's predecessor, Grace Portolesi was announced as the Labor candidate for Hartley, turning the seat into a three-way contest.In early polls in January 2018, Xenophon was predicted to win Hartley, with articles naming Xenophon as the most influential person in South Australia.Despite being written off by the media, Tarzia went on to win the three-way race and retain Hartley convincingly, with 57.8% of the vote and a 4.7% swing towards him, despite a statewide swing of 1.1% against the Liberals.