As for Le Pen, Right wingers disenchanted with Sarkozy, who'd never vote Socialist - what're they gonna do?
That's exactly what I mean, though. Parties that traditionally occupied the left or right are moving towards the centre, so if you're a traditional left/right leaning voter, the only options remaining are the parties at the extremes of the spectrum.
It happened in the UK with the Labour party. I woke up one morning and found they were no longer left wing. Now the only proper left-wing party we have is the extreme Socialist Workers Party. The SWP is actually too left wing for me... but what are my other options?