Our own experience, as well as that of other countries, demonstrates that merely being rich is no bar to a society's retreat into rigidity and intolerance once enough of its citizens lose the sense that they are getting ahead. [...]

But it would be equally foolish to ignore the effects of two decades of economic stagnation for a majority of the nation's citizens in bringing about these hanges. And it would be complacent not to be concerned now that the economy's prospects are in question once again. The history of each of the large Western democracies --the United States, Great Britain, France, and Germany-- is replete with instances of just this kind of turn away from openness and tolerance, [...]

The attitude of people toward themselves, toward their fellow citizens, and toward their society as a whole is different when their living standard is rising from when it is stagnant or falling. It is likewise different when they view their prospects and their children's prospects with confidence as opposed to looking ahead with anxiety or even fear.

Friedman, Benjamin M. The Moral Consequences of Economic Growth

I agree and I suspect this is not only the case of the CDU. This is a tad too often given a racial twist... I don't know about the Poles in Germany, but the spanish or italian immigrant waves decades ago were not exactly met with flowers and red carpets in the south of France. This kind of clash of cultures is intrinsic to international migration.
Recent anti-immigrant reactions could well be fueled by a sentiment of being overwhelmed rather than enriched by the new culture.
Funny enough, there was a report on France 24 the other day about young german-turks returning to Turkey to profit opportunities there and away from a "blocked" Germany.
What's more worrying though IMO is the situation reflected in this article:
http://www.irishtimes.com/newspaper/world/2010/1026/1224282004386.html

"Long-term surveys are more reliable of public opinion and they suggest more stable and moderate views, but it's far from a happy picture.
Two-thirds (69 per cent) of migrants say they feel happy in Germany, according to a survey commissioned earlier this year by the Bertelsmann Foundation.
However, every second migrant says they don't feel accepted by German society, a figure rising to 61 per cent among those with Turkish roots. One in four Turks feels utterly alien in Germany"

Free at last! Free at last! Thank God Almighty, we are free at last! (Martin Luther King)