The most common and most likely answer to this crossword clue is the 8 letter word POLITICO
I've seen this crossword clue in Financial Times
P
O
L
I
T
I
C
O
More clues leading to the result POLITICO
- Copilot I misrepresented as MP perhaps
- One jerk entering the game as a parliamentarian?
- Mostly well-mannered, endlessly nice and ordinary government minister, perhaps
- Schemer, drunk in charge, in serious trouble?
- Party creature, say, one taken in by cool tip when drunk
- Party person, one with nervous habit during game
- I introduced unusually cool tip for one to get the party going
- One involuntary movement in game generally played by upper class member
- Copilot I dressed up as a party person
- Partyman got it before '99 in a game
Buddy explains!

The straight part
We know that "Schemer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case schemer = politico.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 POLITICO mean?
POLITICO noun- A politician.