Bill Clinton a force for Hillary on the campaign trail

Bill Clinton made his first solo campaign appearance for his wife, the former US Secretary of State Hillary Clinton, in New Hampshire this week.

The former president already campaigned on her behalf eight years ago during her first attempt at winning the bid for the White House.

Political experts disagree on whether his presence helped Ms Clinton the first time around.

With conservative candidates like Donald Trump already targeting Mr Clinton for his past infidelities, the BBC's Anthony Zurcher asks if this time the skilled campaigner can be a force for good or evil.