John Dean may be right, but there is a paradox nested in the heart of his warning. The reason why Nixon might have survived Watergate if he had a vibrant partisan media willing to lie to cover for him is because public opinion matters.

The concern about Fox News is that it will defend Trump no matter what nefarious facts come out and thus the Fox audience will remain loyal to the President and will push back against any political effort to remove him.  But even in the age of Fox, Trump is really unpopular with the general American public. Fox may have created a bubble universe where a portion of the population lives and sees only a righteous Trump being attacked with baseless claims by his political enemies, but that portion is a minority that does not seem to be growing. In fact, it is shrinking and even with Fox and the rest of the wingnut media universe, Trump is polling worse than Nixon did.

Dean's concern that Fox et. al. will preserve Trump's popularity no matter what facts come out in the various investigations ignores the fact that he doesn't have much popularity and never has. If the loss of the President's popular support is what really gave teeth to the Watergate scandal, Trump lost that before he even got into office. Even with the entire rightwing outrage machine, he is never likely to have the public behind him.