And being an activist does not mean, well, being active.  Lots of people are active.  They're not all activists.  

Great activists use their skills and talents and resources to draw attention to an issue or cause, to start a dialogue and get the ball of reform rolling.  Those skills and talents and resources do not always translate well into legislative or executive prowess.  Some people make it work, of course.  But I suspect those people were all along more cut-out for politics than activism.  Politics often requires you to give up that very courage and idealism and independence from the Establishment that make people become activists.  It's often a trade off of freedom for results.  I mean, go look at Swedish fish's diary.  We can all sit here and be idealists.  I'd LOVE people like Bove to be in charge.  But to get into that position and stay there requires political savvy and the ability to make people feel secure.  Activists are usually driven to do what they do because the politicians dare not go near their cause and because their cause involves scary things.    

I think in Europe there is more expectation and acceptance of incorporating activism into daily politics (I'm not talking about revolutions and coups - which are also more acceptable in Europe) than in America.  But while it might be easier for an activist to become a politician in Europe, I suspect they probably face the same challenges once elected.  

"Talking nonsense is the sole privilege mankind possesses over the other organisms." -Dostoevsky