Donald Trump's major announcement: A challenge for Obama - Video

Donald Trump has been promising a "big" announcement since Monday. Americans who cared knew that the announcement was going to be about President Obama, but that was all they knew. He appeared on Fox & Friends to tease the announcement, saying it could alter the course of the election, and has also mobilised his social media accounts to get the message out. And now, today, he has made his "big" announcement. And here it is.