Ruth Marcus, a longtime editor and columnist for the Washington Post opinion section, resigned on Monday after her column criticizing owner Jeff Bezos’ changes to the section was scrapped. Bezos announced last month that the opinion section would begin writing in “support and defense” of “personal liberties and free markets” and would not publish viewpoints opposing those principles. Writing to Bezos and publisher Will Lewis, who she says killed her column, Marcus warned that the Post’s new policy “threatens to break the trust of readers that columnists are writing what they believe, and not what the owners has deemed acceptable.”