Question

The sierra club urges its members to contact their senators about a bill to be considered in congress. this is an example of

Answer 1

I believe the answer is: grassroots mobilization.

grassroots mobilization refers to an effort to persuade citizens in certain area to be more involved in politics.
Usually being done by forming a certain activist group that established to advocate for a certain type of legislation. (just like what sierra club does in the scenario above)