The Media Research Center has always done good work exposing media bias, but very little about immigration over the years.
They've issued a special report:Election In The Streets How The Broadcast Networks Promote Illegal Immigration [By Tim Graham, MRC Director of Media Analysis August 28, 2006 Full Report | PDF Version]
I discovered this on Reason Magazine's Hit and Run blog, where Katherine Mangu-Ward deserves some credit for saying
I love illegal immigrants (and their protests) as much as the next guy, but this kind of coverage screws us all in the end. When each side has its own set of facts, it just means more tiresome dinner conversations where everyone accuses the other side of lying and no one ever changes their minds, squabbling even as illegal Mexican busboys clear away the plates after dessert.
My position, as I've said, is "while people are entitled to their opinions, they aren’t entitled to their own facts."