Obama's second point — delivered months before the 2016 presidential election — was a direct rebuttal of isolationism without naming any candidate. He argued from both security and economics: overseas state failures became 'breeding grounds for terrorists,' health crises like Zika or Ebola crossed borders regardless of walls, and global tax enforcement required international cooperation. He then broadened the argument to immigration and religious tolerance. 'Suggesting that we can build an endless wall along our borders, and blame our challenges on immigrants — that doesn't just run counter to our history as the world's melting pot; it contradicts the evidence that our growth and our innovation and our dynamism has always been spurred by our ability to attract strivers from every corner of the globe.' The line 'Building walls won't change that' drew some of the loudest applause of the speech — and when an audience member shouted 'Four more years!', Obama laughed: 'Can't do it.'