As for the Roll-Call article, they contacted the Whitehouse and Rove did not deny the story.
You can't necessarily judge anything by that. Despite the tempest, FR is really a teapot and it's a nothing story nationally, but denying it puts the story on the front burner. Tancredo does not offer the "darken" statement as a direct quote. It doesn't sound like the White House. After all, he's a very minor one out of 435 in an ultra-safe district, I doubt he's on Rove's radar screen.
I really hate to bother you again, but exactly WHERE is that quote?