Martin Luther King Jr’s granddaughter Yolanda Renee King(L) speaks next to student Jaclyn Corin during the March for Our Lives Rally in Washington, DC on March 24, 2018. Galvanized by a massacre at a Florida high school, hundreds of thousands of Americans are expected to take to the streets in cities across the United States on Saturday in the biggest protest for gun control in a generation. / AFP PHOTO / JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)

Saturday’s massive rallies for gun control around the world—more than 800 of them—were centered on the largest of them all in Washington D.C., at the focus of the cause, the capital building. While the size of the crowd was impressive, the events on the stage were even more so. Speaker after speaker delivered powerful orations. Most of the speakers were students from Marjory Stoneman Douglas High School in Parkland, Florida, survivors of the Valentine’s Day shooting that took 17 souls.

Having witnessed the bloodshed first hand and having suffered the loss of close friends, their voices were filled with emotion. Having been the driving force behind the rally, their words were crafted with touching memories, meaningful facts, declarative sentences, and clear calls to action. And having spent the last month promoting the march in many media appearances (Time Magazine featured five of the students on this week’s cover: Jaclyn Coryn, Alex Wind, Cameron Kasky, David Hogg, and Emma Gonzalez) they delivered their words with forceful confidence.

Ms. Gonzalez—whose electrifying speech three days after the massacre in Parkland has made her a viral star with 1.2 million Twitters followers—electrified the Washington crowd again, this time with silence. She paused in the middle of her speech and stood stock still, staring straight ahead, tears streaming down her face for six minutes and twenty seconds. When she resumed, she told the audience that that was how long the Parkland shooting lasted.

However, all those eloquent teenage orators were outshone by a nine-year-old. Yvonne Renee King, Martin Luther King, Jr.’s granddaughter, walked onstage with only a hand microphone—no lectern, no notes, as all the high schoolers used—and in one minute and fifty seconds roused the crowd to a higher level than any other speaker.

Ms. King began:

My grandfather had a dream that his four little children would not be judged by the color of their skin but the content of their character. I have a dream that enough is enough and that this should be a gun free world. Period.

Then evoking her grandfather’s clerical technique of call and response, she said: