Six women of color have left the Nevada campaign of Sen. Elizabeth Warren, D-Mass., ahead of the state's caucuses, complaining about a toxic environment, Politico reported.And the senator has apologized for what they say they experienced in her organization. The staffers have left since November, with three saying they felt marginalized by the campaign, the news outlet reported. "During the time I was employed with Nevada for Warren, there was definitely something wrong with the culture," Megan Lewis, a field organizer who joined the campaign in May and departed in December, told Politico. "I filed a complaint with HR, but...