Graham Platner was all but certain to win Maine’s Democratic Senate primary on Tuesday.

But the swirl of controversies over Platner’s past personal behavior had raised a slew of questions about the outcome: Would there be a significant number of protest votes lodged for Gov. Janet Mills, whose name was still on the ballot even though she suspended her campaign in April? Would Democratic voters skip the race entirely?

None of that came to pass. With votes still being counted Tuesday night, the progressive populist Platner was on course to earn about three-fourths of primary voters’ support — effectively ending any question about whether Maine Democrats wanted him to be their standard-bearer against Republican Sen. Susan Collins in one of the nation’s marquee races in November.

His speech – and the reaction from both parties – set the fault lines for what will be a race Democrats consider critical for Senate control.

‘They don’t know Maine’