Lobbying is an important part of the political process because they represent groups of?

voters

Explanation:

Lobbyist consist of a group of voters that gather together to give their support to certain representatives. They want to legally influence these representatives to create some sort of laws that will be beneficial for them.  

Lobbying tend to be one of the best way that the representatives can do to collect enough fund that they can use to pay for their campaign. Example of famous lobbyist in USA:

- American Medical Association

- National Association of Realtors

- Chamber of Commerce.