Political candidates should not be allowed to deny entry to any media outlet, period. Regardless of one’s relationship with a specific news organization, I believe this action infringes upon the freedom of the press explicitly stated in the First Amendment.
Regardless of perceived bias in The Washington Post, the campaign trail must be open to criticism and speculation from both sides, starting with admittance of all legitimate reporters. If certain media outlets are restricted, politicians and public figureheads cannot be held accountable to the necessary extent.
This is not Trump’s first offense in banning certain media outlets. The Trump campaign had previously banned news outlets such as Politico,