President Donald Trump on Tuesday didn’t clearly condemn white supremacist groups and their role in violence in some American cities this summer, branding it solely a “left-wing” problem and telling one far-right extremist group to “stand back and stand by.”“Almost everything I see is from the left wing, not from the right wing," said Trump, whose exchange with Democrat Joe Biden left the extremist group Proud Boys celebrating what some of its members saw as tacit approval.He was responding to a question from debate moderator Chris Wallace, who asked the president if he would condemn white supremacist and militia groups that have showed up at some protests.