The most common and most likely answer to this crossword clue is the 7 letter word FASCISM
I've seen this crossword clue in The Guardian
F
A
S
C
I
S
M
More clues leading to the result FASCISM
- Soccer bosses scrapping third division — this rule isn’t democratic
- Authoritarian rule of football administrators split when Hearts leaves
- Like group of states restricted by top army officer’s authoritarian government
- … as IMF and Civil Service exercise rigid enforcement of precept
- Fellow orchestrating scams across India for authoritarian rule
Buddy explains!

The straight part
We know that "this rule isn’t democratic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this rule isn’t democratic = fascism.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.