Progressive politician supports US bills (10)

I believe the answer is:

greenbacks

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'us bills' is the definition.
'greenbacks' can be an answer for 'bills' ('greenback' can be a synonym of 'bill'). I'm not certain of the 'us' bit.

'progressive politician supports' is the wordplay.
'progressive politician' becomes 'green' (eg member of the Green Party. I am not sure about the 'progressive' bit.).
'supports' becomes 'backs' (backing is a kind of supporting).
'green'+'backs'='GREENBACKS'

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I've seen this clue in the Sydney Morning Herald.

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