The term “Straw Man” refers to characters who conjure up support for a particular person’s point of view.
 
The term originated in Great Britain and referred to a group of people who were “professional witnesses.”  These individuals would trade testimony for cash at civil and criminal courts.  They would indicate their willingness to do so by walking around court room corridors with a piece of straw in their shoes.  Litigants knew that “straw men” would, for a sum of cash, provide a positive witness for their case.  The term has come to mean a weak or innocuous individual who “fronts” for someone else’s actions or thoughts. 
 
Source: Common Phrases and Where They Come From, Myron Korach, Lyons Press – Division of Globe Pequot Press