There's probably a lot more that has/will/should be written about this issue, but here's just some idle commentary on a Sunday afternoon.
One issue that can generally unite the warbloggers is their hatred of their latest caricature of 'multiculturalism,' their hatred of France, and their belief that France/Europe is going to be overtaken by fundamentalist Muslim hordes which will use their electoral power to institute a fundamentalist theocracy.
Interestingly, it's probably the failure of countries like France to embrace U.S. style multiculturalism which probably gives their "concerns" some legitimacy. France's popular myth about itself, which has been communicated to me with a pretty high degree of sincerity by every French friend/acquaintance I've had, is that racism is not a problem in France. This is because everyone can become French, regardless of skin color or background, as long as they can assimilate and "be French."
Now, this is ridiculous for a variety of reasons. First, it simply assumes away the problem - and, if there is a problem it's the victim's fault. It isn't that you're of African or Arab descent, it's that you aren't French enough. Simple! France already follows the model desired by Ward Connerly - it is illegal for the government to collect racial statistics - which makes it quite difficult to actually demonstrate any racial biases.
But, more to the point it sets up a dichotomous system in which you are either "French" or "not French." Until you are "French" - have assimilated completely - you cannot expect to be a full and normal participant in society. For immigrant communities, this attitude inevitably leads to an increase in their ghettoization. Even if the ideal of full Frenchification is in reality achievable, it isn't easy or realistic for first or even second generation immigrants. So, these communities will stick to themselves, reinforcing their "differences," as well as helping to cultivate and breed resentment.
The much-derided U.S. version of multiculturalism tends to encourage soft assimilation by allowing differences to persist, at least within some fairly broad parameters. There isn't an attempt to quickly eradicate cultural, religious, and ethnic differences and because of that, perhaps paradoxically, a greater degree of assimilation is likely to occur. By allowing people to maintain their cultural identities and simultaneously participate as full members of society (in theory), some degree of conforming to established cultural norms inevitably results.
Anyway, this has all been written in overly simple terms - this is a blog after all - but let me conclude by saying:
Hurray Multiculturalism! Down with the French!
