A good example would be a president bringing iron workers onstage at a rally to show that he has the workingman's interests at heart.
Sentence: the workers were the president's ____ in attempt to win over public support.
Sentence: the president used the workers as a ____ to win over public support.
"Uncle tom" comes to mind, but it is too specific and implies fault on the group being used. I would prefer a term describing the appropriation going on.
Best Answer
A shill is probably the nearest word, although like with Uncle Tom, it is difficult to avoid the connotation that the shills are knowing participants, or at least that in all the circumstances they ought to know.
You can also describe the role of the people involved. You could say they act as window dressing.
"The president used the workers as window dressing to win over public support."
Using this latter device tends to avoid the connotation that the people involved (the window dressing) are at fault.