Liberal groups and senators are standing firm in their embrace of Graham Platner, even as the progressive outsider’s political baggage hangs over Maine’s Democratic Senate primary to take on incumbent Sen. Susan Collins (R-ME).

The former oyster farmer and Marine veteran is wooing lawmakers and voters more aligned with the progressive wing, as well as some unlikely lobbyists, as he seeks to triumph over primary opponent Gov. Janet Mills (D-ME) in a state critical to Democrats’ effort to retake the upper chamber.