WASHINGTON (AP) – President Donald Trump is trying to turn the debate over a wall at the U.S.-Mexico border back to his political advantage as his signature pledge to American voters threatens to become a model of unfulfilled promises. Trump will hold his first campaign rally since November’s midterm elections in El Paso, Texas, on Monday night. It begins a defining weak for his push to build a border wall, one that could impact his presidency and his prospects for re-election. The dispute over funding is threatening to spark another government shutdown. In El Paso, a protest march is scheduled at the same time as Trump’s rally. Joining the march is the former congressman from the area, Beto O’Rourke, a Democratic star and a possible candidate for president.