THERE is one woman who could cause Rudy Giuliani, the former New York mayor, more problems than Hillary Clinton in the race for the White House: she is Donna Hanover, his second wife, writes Sarah Baxter. Hanover, an actress and broadcaster, was enraged by Giuliani’s flagrant infidelity towards the end of their 18-year marriage and the divorce case was vicious. Giuliani’s advisers fear that she could be a loose cannon in the 2008 campaign. Giuliani was acclaimed as the “mayor of America” for his heroic role during the attacks on September 11, 2001 and is revered for his leadership. At...