At the conclusion of a recent op-ed on California's catatonically dysfunctional government, Dan Walters, dean of the Sacramento press corps, makes a memorable observation:

The much-vaunted checks and balances of the American system, designed by the nation's founders who had revolted against a king and feared centralized power, create stasis in a society with as many rival factions as California has.

What may have worked in post-colonial, mono-cultural America doesn't work very well in a postindustrial, multicultural state such as California, especially since we've added even more hurdles to decision-making, such as ballot measures and two-thirds votes.
(State's government is designed to fail, by Dan Walters, Sacramento Bee, October 23, 2009)

Of course the Founders, in the classic words of jack-of-all-trades Founder John Jay, were working in hospitable conditions:

Providence has been pleased to give this one connected country to one united people—a people descended from the same ancestors, speaking the same language, professing the same religion, attached to the same principles of government, very similar in their manners and customs, and who, by their joint counsels, arms, and efforts, fighting side by side throughout a long and bloody war, have nobly established general liberty and independence.

VDARE's Brenda Walker has distilled the same idea for our modern sensibilities:

We all prefer to be around others who speak our language, share our values and understand our jokes. Human community is based upon similarities, not differences. Wouldn’t it be better to develop public policy on the basis of human nature as it really is?

It's worthwhile keeping any or all of these versions of this basic wisdom in mind for the occasions when your acquaintances utter the usual, mindless accolades to diversity. (To arm yourself at the equivalent of the PhD level in diversity realism, get Jared Taylor's The Myth of Diversity under your belt.)