I hate to point this out, but since I've heard it for almost twenty years without any actual evidence to suggest it's happening, it sounds like the same old fairy tale to me. Remember Ruy Teixeira's book?
http://www.amazon.com/Emerging-Democratic-Majority-John-Judis/dp/0743254783
That was in '04. I've been working in statewide campaigns since 2006. Municipal (Houston) campaigns in the off-numbered years. It was great helping Annise Parker get elected, but the truth is she's a corporate Blue Dog. A fiscal conservative. She laid off city employees rather than raise the water bill or assess a garbage collection fee, both among the lowest in the state.
I'm currently working my precinct trying to get the blue vote out for Sylvester Turner, and it's like pulling hen's teeth. Same thing in the summer of 2014, when I had middle-aged female neighbors tell me that thy weren't going to vote because they didn't see the point. D primary voting history but they weren't going to vote for Wendy Davis.
My (almost inside the Loop) precinct in six years has gone from blue to purple to red, all because the Democrats don't turn out. Sorry to pee on the parade but the Latinos don't look as if they're going to show up in my lifetime to save us (and I'm in my mid 50's).