Ronald Brownstein, Columnist

Platner Needs These Collins Voters to Win in Maine

She’s got an ace in the hole.

Photographer: Graeme Sloan/Bloomberg

No primary in the country is dividing the Democratic Party more bitterly than the battle for the nomination to face Republican Senator Susan Collins in Maine. That’s both because the choice is so stark and the stakes are so high.

The nomination contest between Maine Governor Janet Mills and first-time candidate Graham Platner, an oyster farmer and veteran of the Iraq and Afghanistan wars, has become a proxy battle for competing theories about how Democrats can succeed in the Donald Trump era.