This is an installment of Visual Studies, a series that explores how images move through and shape culture.

On July 13, in a “fight or flight” moment, Donald Trump demonstrated himself to be an Olympian performer, making a potent impression by thrusting his fist into the air immediately after an attempt on his life. An iconic image was instantly born.

Watching Mr. Trump co-opt this posture of protest, I couldn’t help thinking about the broader history of political gestures. While doing research for a video installation about political rhetoric, I discovered that there were hardly any dramatic hand movements in televised presidential speeches until George H.W. Bush was inaugurated in 1989. How did our politicians find their way from minimal movement, to polished oratorical gestures, to posing as activists?

Mr. Trump’s raised fist is the latest chapter in the story of a political gesture. Clenching the fist, a signal performed to initiate the “people’s fight,” asserts that one has been victimized by the powers that be.

In America, the gesture is almost synonymous with the Black Panthers, whose raised fists stood against racial injustice and white supremacy. Often accompanied by the cry, “Power to the people,” it was a call to arms by the oppressed, an expression of rebellion and defiance.