noun
fellow party member
Refers to a person who belongs to the same political party as the speaker or another member.
彼は党友と政策について話し合った。
He discussed policy with a fellow party member.
noun
party supporter; party sympathizer
Refers to a person who supports or sympathizes with a political party, but may not be a formal member.
党友の集まりで選挙の応援を呼びかけた。
At a gathering of party supporters, they called for election support.