Bold independent arrived with Republican, and a Liberal to describe US Congress (9)
I believe the answer is:
bicameral
'republican and a liberal to describe us congress' is the definition.
I can't tell whether this definition defines the answer.
'bold independent arrived' is the wordplay.
'bold' becomes 'b' (abbreviation).
'independent' becomes 'i'.
'arrived' becomes 'cameral' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'b'+'i'+'cameral'='BICAMERAL'
'with' is the link.
Can you help me to learn more?
(Other definitions for bicameral that I've seen before include "using two houses" , "Like our parliament" .)