Donald Trump tests the limits of his showman style

Donald Trump descended the famous escalator in Trump Tower one year ago Thursday to launch a presidential campaign that seemed so outrageous, provocative and unconventional that it was dismissed as reality television.

A year later, Trump is the presumptive Republican nominee. His showman style — with its brass-knuckled tactics, defiance of decorum and itchy-Twitter-finger approach — has created a new brand of politics that is entirely his own.