Spaniard's got at in a political role (7)
I believe the answer is:
Here is my best explanation:
'a political role' is the definition.
'spaniard's got at' is the wordplay.
'spaniard' becomes 'senor' ('mister' in Spanish).
'got' is an insertion indicator.
'senor' placed around 'at' is 'SENATOR'.
'in' acts as a link.
(Other definitions for senator that I've seen before include "One of 100 on Capitol Hill", "Member of government", "US politician", "US assembly member", "Member of the Upper House of the US Congress", "Roman politician", "Treason by member of parliament", "US representative", "Member of upper US assembly" and "Member of the Second House".)