The White House stopped just short of dismissing Donald Trump as a clown Sunday - calling him a "sideshow" act with "zero chance" of becoming president. SNIP Trump countered that he represents Obama's biggest nightmare in the 2012 race and that the White house is running scared. "I know for a fact that I am the only candidate they are concerned with," Trump told The Daily News. "They are very concerned because I am challenging him as to whether or not he was born in this country where there is a real doubt." "He should focus on properly dealing with...