Question

Is most likely to support government action to protect and expand civil liberties?

Answer 1

Generally speaking it would be "a liberal" who is most likely to support government action to protect and expand civil liberties, since liberals tend to believe in the value and importance of government intervention. 

Answer 2

Answer; 
Liberals.
A liberal is most likely to support government action to protect and expand civil liberties. 
A Liberal believes in personal freedom over order in society, liberals tend to believe in the value and importance of government intervention
A conservative on the other hand uses tradition and heritage when seeking guidance.