EDIT: When Le Pen and FN win the next election, they will by definition no longer be extremist, having demonstrated they represent a majority/plurality of the population rather than an extreme fringe.
Sorry, the definition don't depend on the majorities, depend on facts, positions, statements. They are the garbage of Europe; populism, nationalism, loud voice and no brain. They can do or say wherever to get some attention or votes.
Just like you.