RACHEL MADDOW (HOST): But John Tanton kept it up. It's been his life's work. He has founded lots and lots of different anti-immigrant groups over the years. And the two that have really stuck and really succeeded are a group called FAIR and a think-tank originally founded as a project of FAIR, called the Center for Immigration Studies. You ever heard that name before? Center for Immigration Studies? If you heard that name today, it's because that name, Center for Immigration Studies, appears on screen in the brand-new Donald Trump ad that came out today. Ten seconds into the 30-second ad. This is the first ad that Donald Trump has run in the general election and right out of the gate, he's citing the Center for Immigration Studies. The head of the Center for Immigration Studies has also met with Donald Trump during his campaign. His campaign has also bragged about that in print. The Center for Immigration Studies is part of this network of anti-immigrant groups that have been founded over the years by John Tanton that you see here. John Tanton has kept watchdog groups like the Southern Poverty Law Center and People for the American Way very busy over several decades as they keep trying to point out his background, right, as they keep trying to remind people who he is, as he drifts in and out of overt white supremacist circles and eugenics groups and continues to found and serve on the board of groups that advocate anti-immigrant policies. And a lot of -- the reason those watchdog groups are so busy about him is that some of these John Tanton groups make a point of trying to make themselves seem very mainstream, very much like normal Republican and conservative organizations, but honestly they're all part of the same network, they're all founded by the same guy, and they never stay camouflaged for all that long. They end up reverting to form.

The Center for Immigration Studies, for example, will distribute essays from Holocaust deniers every now and again. Oops. They keep finding themselves digesting and sending around work by white nationalists. I mean, you get back to that dark side. You slip back into that really fast when you're circulating arguments like, “the native ethnic stock that founded and built the U.S. is systematically being replaced through massive third world immigration.” “Native ethnic stock.” For the first national Donald Trump ad of the presidential election to be overtly citing the Center for Immigration Studies, the John Tanton group, that's nuclear.

Previously:

The Daily Beast Highlights “The Shady Network” Of Nativist Organizations Trump Cited In His Speech

Media Run With Discredited Nativist Group's Research To Claim More Than Half Of Immigrant Households Receive “Welfare”

CNN Cites Discredited Anti-Immigrant Group To Stoke Fears About Undocumented Immigrants Exploiting Birthright Citizenship