The thing is Twisty, if you look at the historical support for this scumbag, you’ll see that it hasn’t actually changed much in all the time he’s been running. Furthermore, at the last set of elections some staggering proportion of voters who voted for him in the first round (something like 80%) said in an exit poll that they didn’t actually want him to win, they just wanted to register a protest vote.
What was different this time? Simply a particularly low turnout (23%, as you said), which allowed the protest votes and kooks to be more dominant than they usually are. Combined with a late surge in unpopularity for Jospin and an apparent cleaning up of Le Pen’s act that allowed a few self-deluded voters to choose him.
He’ll be creamed by Chirac in the final vote, with a much much lower percentage than he got in this first round.
I agree that the rise of the European right is a touch concerning but I wouldn’t read too much into this specific vote.