Fox News host Rachel Campos-Duffy attacked Americans who are under 30 years old after Australia banned tennis star, Novak Djokovic, over his refusal to get vaccinated for Covid-19. "It is a warning," Campos-Duffy said during a Fox News segment. "And I think that the only reason that it hasn't happened here are, one, obviously we have some constitutional protections but just in terms of talking about the mindset.