noun
proponent
pruh-POH-nunt/prəˈpəʊnənt/
A person who supports an idea, plan, or cause.
The playground proponent presents the model enthusiastically to two listeners.

Etymology
A proponent literally “puts forward” something for consideration. The word first named someone presenting a proposition or argument, connecting advocacy with bringing an idea before others.
In context
Betsy DeVos is a proponent of the for-profit colleges she's brought in people from the for-profit colleges
More examples
- Proponents of the plan say it will reduce traffic.
- As a proponent of exercise, he encourages daily walks.
- The proposal lost its strongest proponent when the mayor resigned.
Forms
proponent · proponents