Socialism, despite its history of failure, has become mainstream this year and is being adopted by Democratic politicians as their go-to economic policy, former United Nations Ambassador Nikki Haley warned Monday. “2020 was the year socialism went mainstream,” Haley wrote on Twitter. “The dangerous ideology, which has failed everywhere it has been tried & ruined countless lives, is on its way to becoming the default economic policy of the Democratic Party.” “This terrifying trend threatens the future of every American,” she added. Haley made similar comments about socialism last week while voicing support for Republican Sen. Kelly Loeffler, who is set to face off Democratic challenger Raphael Warnock in Georgia’s runoff elections. “This is the Democratic Party that believes you cancel anyone that doesn’t agree with you,” she said. “They believe that you defund the police and stop taking care of those that serve us. They believe that socialism is …