Democratic Maine Senate nominee Graham Platner's team quietly fielded a poll Tuesday gauging the strength of people who could replace him on the ballot, as pressure mounts for him to drop out of the race. The flash poll, obtained by POLITICO, was conducted by Public Policy Polling and commissioned by Platner's campaign, according to a person with knowledge of the survey who was granted anonymity to discuss it. It tested head-to-head matchups between Republican Sen.