Graham Platner, a military vet and oysterman from a small town in Maine, will run for U.S. Senate as a Democrat in an effort to oust Republican Susan Collins.

Graham Platner, a Democrat from Hancock County, joins a growing list of mostly little-known candidates to challenge Collins, who is seeking a 6th term.

Platner, a Democrat who served as a Marine in Iraq and the Army in Afghanistan, says the "oligarchy is the enemy."