Maine Senator Susan Collins is trailing Democratic challenger Graham Platner by 9 points, a rare populist threat to her seat that's bad news for establishment incumbents tied to AIPAC and corporate donors.

• Platner, an Iraq war veteran, is hammering Collins for voting to start the Iraq war and repeatedly voting against troop withdrawal.
• Collins responded by blaming Platner for choosing to enlist, a tone-deaf jab at a vet with PTSD.
• AIPAC has given Collins $1.8 million; Platner has taken zero, which is why Washington media and establishment Democrats are attacking him.
• The Democratic party itself is sending corporate Democrats on TV to trash Platner over old tattoos and his refusal to court donors.
• Other anti-establishment candidates like Shortcut Trucker Barti (Pelosi's old district) and Tommy Steyer are getting the same media treatment for refusing donor money.

Outlook: Platner's lead is widening and Collins looks likely to lose her seat in November, a sign populist Democrats can beat long-time incumbents when they reject AIPAC and corporate money.