Opposing the genocide of brown people? Extremism.
Opposing nakedly corrupt fascism? Extremism.
Opposing omnicidal destruction of the climate for the benefit of a few oligarchs' pockets? Extremism.
Opposing having your livelihood stolen and the creation of an Orwellian panopticon all rolled up into one? Believe it or not, extremism!

Huh, it's almost as if the ghouls controlling the definition don't have the People's best interests at heart.

(Oh, and also: attempting a coup in order to install a dictator? Somehow, not extremism.)