New York Mayor Bill de Blasio made his case for president in an appearance on ABC's "Good Morning America" after releasing a video announcing his candidacy on YouTube earlier Thursday morning. . He made it clear a large part of his strategy will be to attack President Donald Trump. "Donald Trump is playing a big con on America, I call him 'Con Don' every New Yorker knows we know his tricks, we know his playbook. I know how to take him on," he told ABC Chief Anchor George Stephanopoulos. Trump wasted no time firing back. Within minutes, he tweeted de...