WASHINGTON — Former President Donald Trump has filed suit against three of the country’s biggest tech companies, claiming he and other conservatives have been wrongfully censored. But legal experts say the suits are likely doomed to fail, given existing precedent and legal protections.Trump announced the action against Facebook, Twitter and Google’s YouTube, along with the companies’ chiefs Mark Zuckerberg, Jack Dorsey and Sundar Pichai, at a press conference Wednesday in New Jersey, where he demanded that his accounts be …