He used to be on Fox News a lot talking about what was going on at the border and the illegals. He wanted to run for President in 2012 but the establishment did not want him making speeches on illegals and he was shut out. Shortly after that he was no longer on Fox News. He sees a chance to stop the illegals with Trump.
And .. we can all hope Trump is smart enough to use him and his extensive knowledge.
Who knows, he and Trump may already be talking; privately.