All eyes on US Senate race as Graham Platner, embroiled in controversy, is set to advance as Democratic nominee All eyes on US Senate race as Graham Platner, embroiled in controversy, is set to advance as Democratic nominee Voters in Maine head to the polls on Tuesday for one of the most closely watched primary elections in the country. The US Senate race has become a national fixation as Democrats try to unseat a longtime Republican with a political newcomer who has spent months under fire .