Donald Trump's ad begins with a shot of President Obama and Hillary Clinton. Then comes a U.S. battleship launching a cruise-missile strike. From there it moves swiftly through an explosive montage: The suspects in the recent California terrorist attack. Shadowy figures racing across the U.S.-Mexico border. Islamic State militants. The narrator, a deep-voiced man, speaks ominously: "That's why he's calling for a temporary shutdown of Muslims entering the United States, until we can figure out what's going on. He'll quickly cut the head off ISIS and take their oil. And he'll stop illegal immigration by building a wall on our...
