Otdfbt

I like the word prop.

Prop: something used in creating or enhancing a desired effect

Often it has a negative association because it is generally used like "The President used the iron workers as props"; using frequently means to take advantage of.

Sentence: the workers were the president's token in attempt to win over public support.

Sentence: the president used the workers as a token to win over public support

token English Oxford Living Dictionaries

1. a thing serving as a visible or tangible representation of a fact, quality, feeling, etc..

This term contains the inference of appearing to align per the given context without implying fault on the group being used.

I've usually heard them referred to as a "Poster Child," a reference to a proverbial propaganda poster.

someone or something that is used to represent a particular quality:

-Cambridge Dictionary online

The people appearing on stage are the speaker's pawns. Consider the definitions from Merriam-Webster:

1 : one of the chessmen of least value having the power to move only forward ordinarily one square at a time, to capture only diagonally forward, and to be promoted to any piece except a king upon reaching the eighth rank

2 : one that can be used to further the purposes of another

Literally, as in definition one, a pawn is a playing piece from the game of chess, often regarded as having little value but still able to be used strategically by a skilled player. Figuratively, as in definition two, a pawn is not unlike the chess piece, not really important, but able to be used by a shrewd and cunning political player to advance his or her agenda.

Two different words, for two difference sentences.

Sentence: the workers were the president's dupes in attempt to win over public support.

From Merriam-Webster: A dupe is "one that is easily deceived or cheated".

Sentence: the president used the workers as props to win over public support.

See the @UnhandledExcepSean answer.

The term [Catspaw]1 (sometimes written "cat's paw") means a person who is unwittingly used as a tool by another person. It's similar to a pawn, but implies some gullibility on the part of the person being so used. The term supposedly originates from a fable about a monkey who tricks a cat into burning its paws for the monkey's gain.

No Nigel, I shan't be your catspaw in this matter. You must deal with the consequences yourself this time.

The expression smoke and mirrors may apply here:

Something that is described as smoke and mirrors is intended to make you believe that something is being done or is true, when it is not:

• The new budget isn't smoke and mirrors; it's an honest attempt to reduce the deficit.

(Cambridge Dictionary)

• the President used the workers as smoke and mirrors to win over public support.

A fig leaf (sometimes hyphenated) is something that is used to (figuratively) cover up something that you do not want seen:

something that conceals or camouflages, usually inadequately or dishonestly

So the second sentence would be

The president used the workers as a fig leaf to win over public support.

This is an allusion to the book of Genesis, in which Adam and Eve cover their nakedness with literal leaves from fig trees. It has come to connote a transparent attempt to distract from one's true motivations, e.g.:

“Is Russia really committed to a peace process or is it using the peace process as a fig leaf to try to deliver some kind of military victory for Assad that creates an Alawite mini state in the northwest of Syria?” Hammond told reporters in Rome.

"Britain says Russia trying to carve out mini-state for Assad in Syria", Reuters, 2016-02-02

The austerity agenda has been seized by the Tories as the fig leaf behind which to progressively underfund health and social care, creating today’s crisis.

"Jeremy Hunt is still clinging to his job because he has big plans for April", New Statesman, 2019-02-04

The word "claque" is close to what you want. It is defined bas a group of sycophantic followers, as in "The President was surrounded by a claque of scheming bureaucrats," or an organized body of professional applauders.