A physical barrior is a required component of a secure border on the southern United States border. Evil and criminal activities would be reduced or eliminated. This is common sense and is affirmed by the results in the areas where a wall is currently installed.
It is true that no wall is totally 100% effective. But neither are home locking systems. It is possible for someone to break into any house even though it becomes increasingly difficult as home entry protection is increased. Neither the home nor the United States border should be left without physical protection barriors even though neither is perfect.
President Trump has repeatedly promised a wall (wall system) on our Mexican border. It has become an extremely difficult thing to achieve. But it must be done. If President Donald Trump cannot achieve this, despite his best efforts, then it is time for someone else to take a different approach, a more powerful approach. Failure is not an option.