Voters are headed to the polls on Tuesday for primary elections that include a crucial Senate race involving the scandal-haunted Graham Platner.In Maine, Platner is favored to win the Democratic primary after his main opponent, former governor Janet Mills, suspended her campaign. The incumbent senator, Susan Collins, remains safely at the top of the Republican ticket – just slightly behind newcomer Platner’s lead in polling.But the oysterman and marine veteran’s string of controversies, ranging from alleged “toxic” behaviour towards women to a tattoo recognised as a Nazi symbol, has plunged Democrats into debates about double standards, purity tests and not...