WASHINGTON — Rep. Billy Long thinks he has two paths to winning the Republican primary for U.S. Senate in Missouri. The first is the path of Kathy Barnette in Pennsylvania. After losing a congressional bid in 2020, Barnette set out to find voter fraud in her district based on a faulty statistical analysis of her race. In the process, she became a prominent figure in election denial circles, providing her with enough grassroots support to keep up with Trump-endorsed Mehmet Oz and billionaire David McCormick, both of whom spent millions on the race. Barnette, after a late surge, finished in thir…