proponent
https://gyazo.com/89474c053b3188180f50800516180a5c
source: By Whoisjohngalt - Own work, CC BY-SA 4.0
noun
a person who advocates a theory, proposal, or project:
｟かたく｠ 支持者; 提案者, 発議者
e.g. a collection of essays by both critics and proponents of graphology.
ORIGIN
late 16th century: from Latin proponent- ‘putting forth’, from the verb proponere (see propound).