The End of Dean?

It is far too early to write off Howard Dean (how I have learned the dangers of writing off Dean). Iowa is not that important and Dean is still running the best funded campaign. However, Blogstar Josh Marshall does raise an interesting point:

If you concede the premise that he has pushed the other candidates in this [strongly anti-Bush] direction (and there's certainly an argument to be made), then it almost reads like saying he's acheived his historical purpose (pushing the Dems to confront the Bush) and now, well, what's the point? Maybe he pushed them in that direction, but he's not the best one to actually run against Bush. And if Kerry and Clark or Edwards have now adopted Dean's approach, why do you need Dean?