[freddie_mercury]

That's literally what it says in the very next sentence.

"In this usage, it referred to those Americans who did not join in the large demonstrations against the Vietnam War at the time"

[astura]

It was stealthily changed. Someone else quoted the original further down in the comments

> The “silent majority” was used by President Richard Nixon during his presidency and his campaign against the Vietnam war. He spoke to the people who were not actively voicing their opinions and who were overshadowed by the vocal few who were supporting the war.