The most common and most likely answer to this crossword clue is the 8 letter word DINGBATS
I've seen this crossword clue in Financial Times
D
I
N
G
B
A
T
S
More clues leading to the result DINGBATS
Buddy explains!
The straight part
We know that "American idiots" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case american idiots = dingbats.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 DINGBATS mean?
DINGBATS noun- A silly, crazy or stupid person.
- A special ornamental typographical symbol, such as a bullet, an arrow, a pointing hand etc.
- An architectural style of apartment building, where the second storey overhangs an area for parking cars.
- A kind of word puzzle involving pictures or typography that hint at the solution.
- Anything that can be thrown or swung with force against something else.
- A small device or gadget, the correct term for which is forgotten or unknown.