He built 23 miles of new wall in 4 years. The wall is a pretend solution. They are tunneled under and climbed over. They are flown over. Most drugs and illegals come in through the port of entry. The FBI is clean. Trump wants to take it over. He wants his Gestapo.
Polls are meaningless at this time.
It the question of the efficacy of walls is the issue, consider that Obama has walls around his homes in DC and Chicago...and probably around his Martha's Vineyard estate.
