Former Republican Congressional Tom Tancredo said that Judge Sonia Sotomayor's joining the National Council of La Raza was like joining the KKK.
So lets check that out.
Here's the homepage of the National Council of La Raza filled with information on news, events, policy, health, affiliates, programs, education and employment opportunities, etc.
(Screen grab):

Here's the home page of the KKK filled with half stories of oppression of whites a nice link that list among requirements that the Klanslive their lives as honorable decent white people. No one else is admitted apparently.
They also declare on the front page that they will no longer settle for rallies, and on another page call for volunteers who will write letters to editors supporting 'white separatist views' and go under cover to infiltrate political parties.
One seems like an organization to help people, and another looks like the home page of a highly partisan group.
On the issue of whether La Raza is like the KKK Barb Shelly of the Kansas City Star in "Sotomayor uproar: "New racism" nothing like the old racism " writes:
Really? Who exactly has La Raza lynched? How does a forceful stand for political and economic equality get mixed up with the foulest stain on our nation's tapestry?
and brings in even more analysis with:
I like the way Denver Post columnist Mike Littwin rebuts that nonsense:
Forget about a post-racial America. Now we've moved to some new kind of racial world, in which the R-word is no longer reserved for, say, Bull Connor or someone standing on schoolhouse steps shouting "segregation forever," but also for a Supreme Court nominee making a point about gender and ethnicity on the bench at a conference about, yes, gender and ethnicity on the bench.
Sotomayor wasn't exactly artful when she made that remark in 2001. But if the new racism is claiming that a Latina judge's experience might lead her to a more informed decision in some cases than a white male's experience, we've come a long way.
Ms. Shelly also talks about the de facto separate and unequal schools that minorities get in the inner city and other indications of a continuing white supremacy in the US.