the.com/grassroots movement

means A political or social campaign built from the ground up by ordinary people organizing locally, rather than one directed top-down by parties, corporations, or elites.

from Straightforward botanical metaphor: grass roots are the hidden, humble underpinnings beneath the visible blade, the part that actually anchors the plant to the earth. The literal phrase existed in agriculture and mining (where 'grass roots' meant the topsoil or the earliest, surface-level stage of a mineral deposit) before it got political. Its figurative use — meaning the common people as the true foundation of a movement, as opposed to leadership at the top — took hold in American political language in the early 20th century, gaining particular traction in populist and progressive movements, and it's stayed the default word for organizing that starts with ordinary citizens rather than institutions ever since.