President Trump left Washington on Thursday on a trip to McAllen, Texas, that he did not want to take to discuss a crisis on the border that Democrats say does not exist. Their disagreement has led to a protracted shutdown affecting vast swaths of the federal government that have nothing to do with the construction of a wall between the United States and Mexico. But as the government shutdown neared the end of its third week, the president left Washington with no additional negotiations scheduled with congressional leaders. In remarks to reporters on Thursday, Mr. Trump left open the possibility...