Mr Paul's beliefs are out of favour with the modern Republican party but they represent a very important strand of American political thought: Mr Paul is a rational believer in freedom.
He is not, we may surmise, a social conservative, who wants the government to take an interest in what is going on in America's bedrooms. In fact he does not want the government to take an interest in anything much: he wants it gone from people's lives.
He does not want American power to be projected around the world because he does not want American power to be vested in Washington. He prefers the notion that local control, local democracy, local power, is the genius of the American way.
Mess with it and you get 9/11.
Mr Paul speaks, at least in part, for many Republicans who feel their party has been hi-jacked in recent years by two groups who do not really speak for them: the religious conservatives and the neo-conservatives.
Source: BBC, Giving the US minnows their moment, by Justin Webb