U.S. President Donald Trump declares Antifa a terrorist organization, despite its decentralized nature, in a move to crackdown on left-wing activism.

Experts question how Trump will accomplish this, saying antifa is more of a concept than an organization with a headquarters and leadership structure.

U.S. President Donald Trump declares Antifa a terrorist organization, despite its decentralized nature, in a move to crackdown on left-wing activism.