Prime minister loses case for state (6)
I believe the answer is:
Here is my best explanation:
'state' is the definition.
(Israel is an example)
'prime minister loses case' is the wordplay.
'prime minister' becomes 'disraeli' (I've seen this before).
'loses case' means to look at the middle letters (the case is the outside letters).
The central letters of 'disraeli' are 'ISRAEL'.
'for' is the link.