The most common and most likely answer to this crossword clue is the 7 letter word TRIPODS
I've seen this crossword clue in The Guardian
T
R
I
P
O
D
S
More clues leading to the result TRIPODS
Buddy explains!

The straight part
We know that "supporters" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case supporters = tripods.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TRIPODS mean?
TRIPODS noun- A three-legged stand or mount.
- A man with macrophallism.
- To enter the tripod position showing signs of exhaustion or distress.