fellow traveller

The phrase "fellow traveller" typically refers to an individual who shares similar political or ideological beliefs with a group or movement, but is not explicitly a member or card-carrying supporter. It originated during the mid-20th century, particularly in the context of the communist and socialist movements. A fellow traveller may sympathize with or advocate for the cause, without officially joining or aligning themselves with the organization or party. It can also imply someone who supports or associates with a person or group despite not fully sharing their beliefs or objectives.