Crossword Genius

Politician's function to stop terrorists' influences (7)

Ross

I believe the answer is:

impacts

I'm a little stuck... Click here to teach me more about this clue!

'influences' is the definition.
(I know this)

'politician's function to stop terrorists'' is the wordplay.
I cannot really see how this works, but
'function' could be 'act' (I've seen this before) and 'act' is found within the answer.
'politician's' could be 'mps' (Member of Parliament) and 'mps' is found in the leftover letters.
A single letter 'i' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...

Can you help me to learn more?

(Other definitions for impacts that I've seen before include "Bumps into, collides with" , "Collisions of jolts" , "It's camp (anag)" .)

I've seen this clue in The Guardian.
Want a hint initially instead of a full solution? Install my app