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.

A largely unknown oysterman and military veteran, Graham Platner garnered widespread attention this week when he launched a U.S. Senate campaign to try to unseat long-time Republican U.S. Sen. Susan Collins.

Graham Platner, a 40-year-old Army and Marine veteran who served four combat tours in Iraq and Afghanistan, launched his campaign for the Senate in Maine on Tuesday, joining a growing Democratic primary field seeking to take on Republican Sen.