Rand is part of a political dynasty although hardly from the Republican Party establishment.

His father Ron - also a physician turned politician - ran as a Libertarian for the US Presidency twice on a platform championing free markets, small government and a ferocious determination to keep the state out of individuals lives. Rand shares many of his father's ideas but his challenge now is making them palatable to a majority of the Republican party and a majority of people in the country. Many ask if he could pose a serious threat to Hilary Clinton by greatly expanding the Republicans' appeal and reaching out to African Americans and young voters. Some praise Rand Paul for his unconventional yet pragmatic approach - TIME magazine recently called him "the most interesting man in US politics." But some see him as a wolf in sheep's clothing and a dangerous isolationist.

In this edition of Mark Coles asks who exactly is Rand Paul - the man who eschews small talk but embraces loud shirts and turtle neck sweaters?