Donald Trump experiences his worst day in the race as some polls no longer show him as the frontrunner. Tune into World News Tonight with David Muir .\r<br>\r<br>Donald Trump experiences his worst day in the race as some polls no longer show him as the frontrunner. Donald Trump continues to lead Republican U.S. .\r<br>\r<br>Oct. 23 -- Bloombergs Mark Halperin and John Heilemann sit down with Republican presidential candidate Dr. Ben Carson to get his take on being the new .\r<br>\r<br>Republican presidential candidate Donald Trump delivered remarks at a campaign event in Miami. donald trump spoke at his miami campaign rally where he .
