Politician objected to being progressive (7-6)

'being progressive' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'politician objected' is the wordplay.
I cannot quite understand how this works, but
'politician' could be 'liberal' (I've seen this before) and 'liberal' is located in the answer.
'objected' could be 'minded' (minding is a kind of objecting) and 'minded' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

'to' acts as a link.

Can you help me to learn more?