WASHINGTON (AP) — President Donald Trump said Friday that he was banning CNN, MSNOW and Politico from the White House due to what he called unfavorable coverage, and threatened that more such media prohibitions could be coming — offering his administration's latest test of constitutional First Amendment protections guaranteeing the freedom of the press.

Trump has long bristled at news coverage he maintains casts him in a negative light, and has a history of filing lawsuits against news organizations, while lashing ou...