What in the world is this author so afraid of? A candidate today, in our age of identity politics, would be proud to have as many different ethnic markers in his DNA as possible. I still think Ted Cruz should have had some fun with being a mix of Irish, Italian and Cuban. He should have offered to dress as a leprechaun at the next debate if Trump would wear lederhosen or a kilt.
The only genetic high risk conspiracy theory I can think of would relate to Obama's parentage. And that one was always a real stretch.