President Joe Biden insisted on Friday that Democrats will win next week’s US midterm elections, but warned of a difficult two years if polls showing Republican victories prove correct. The 79-year-old, on a multi-state push in the final days before Tuesday’s ballot, said he was optimistic his Democratic Party could prevail. “Folks, I’m not buying the notion that we’re in trouble,” he told an audience in Chicago. “I think we’re going to win. I really do.” Polls show Republicans poised for potentially big victories in Tuesday’s congressional election, hoping to win control not only in the House…