Proponents adjectives are listed in this post. Each word below can often be found in front of the noun proponents in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing PROPONENTS.
active, american, ardent, chief
contemporary, earliest, early, enthusiastic
foremost, influential, key, main
major, many, most, original
other, outspoken, prominent, strong
strongest, vocal
Hope this word list had the adjective used with proponents you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.
Please add more adjectives to make this list more complete: