She paints political rival as a dangerous hothead who cannot be trusted with the nuclear codes

Initially caught off guard, Hillary Clinton's campaign has swung between defiance, counterattack and painting Donald Trump as a mortal danger since the FBI director revived her email scandal.

The decision, announced by James Comey in a letter to lawmakers on Friday, initially dumbfounded Clinton and her allies, throwing what was already the country's ugliest presidential election into spasms of shock.