As I said, it only appears in the title they made up for the article and not in the body of his letter. Even in the title the words “Deep State” are not in quotation marks. Only the words ‘contaminated the entire political elite’ are in quotes in the title and in his letter.
”Up until now, certain aspects of the political platform of the Republican Party were able to be overlooked to some extent due to the much more serious threat embodied by the Democratic Party. But it is now evident that the action of the deep state has contaminated the entire political elite without distinction, even involving Donald Trump, who up until now seemed to be a source of hope for the future of the United States.”