Paul is a prophet deserving honour in warning on America's limits
He rails against the "American empire" that "brought the September 11 attacks on us". He condemns Obama for killing Osama. He is indifferent to attempts to prevent Iran obtaining nuclear weapons.
He defends Julian Assange and lauds Bradley Manning, the soldier accused of leaking US secrets to WikiLeaks, a "true patriot". And he is barred from addressing a Jewish forum because of his "misguided and extreme views" on Israel.
Who is this crazed left-wing radical? If you're not closely following the Republican presidential race, you might think he was Noam Chomsky or Michael Moore.
In fact, he's Ron Paul: the free-market crusader, cultural conservative and intellectual godfather of the Tea Party movement, from (of all places) Texas.
He's also the only Republican candidate other than Mitt Romney to place well in two very different electorates: Iowa and New Hampshire.
Paul won't win his party's nomination to run against the President, Barack Obama: his support base is solid, but not broad. Yet his candidacy could prove to be a harbinger of what is next for American politics. As leading neo-conservative commentator Charles Krauthammer recognises: "Paul is out there to build a movement that will long outlive this campaign."
The 76-year-old Paul's most endearing quality is that he has sincere beliefs - support for social tolerance, free-market capitalism and a healthy scepticism towards foreign military adventurism - and he is not afraid to yell them out. That sets him apart from the pack in this age of focus groups and media spin.
Most pundits highlight Paul's rigid adherence to libertarianism, most notably his pledge to slash the federal Leviathan. But he is also the political heir to the notion of American decline that has gained intellectual currency.
In 1987, Paul Kennedy's The Rise and Fall of the Great Powers, which argued the US was in danger of "imperial overstretch", became an international bestseller.
Since then, a plethora of books and articles - including most recently "Is America Over?" (the cover of the prestigious Foreign Affairs) - have declared the end of a Pax Americana and urged more modest visions for the US role in a plural world.
Meanwhile, Americans are suffering from foreign policy fatigue. For 70 years - first against fascism, then communism and more recently against militant Islam - they supported and sustained a defence commitment of the most intense and comprehensive kind. Everything else was subordinated to it; all sorts of domestic concerns were neglected.
Today, there is no Hitler seeking global hegemony. Yet a cash-strapped Washington spends more on military than the next 15 top nations combined. Since both Iraq and Afghanistan have cost America dearly in blood and treasure as well as credibility and prestige, there is overwhelming support for a more prudent approach to foreign affairs and a respite from responsibilities.
Only 33 per cent of Americans, according to a 2010 Chicago Council on Global Affairs survey, think the US will remain the world's leading power in decades to come.
In acknowledging an ambitious foreign policy is incompatible with the goal of cutting spending, Paul is behaving like a true fiscal conservative. After all, if you oppose big government, why exempt the biggest part of the state - the Pentagon - from scrutiny? In the post-September 11 decade, annual US defence spending has risen 70 per cent to about $700 billion.
Now, one can reject Paul's views on the Federal Reserve and the US-Australia alliance (both of which he would scrap) and still accept his thesis the US is in decline and it should come to grips with this reality. In doing so, US leaders would be in a better position to deal with the long-term structural problems plaguing the nation.
True, the US remains the world's largest economy and its lone military superpower. But the US, far from remaining the world's policeman, is bound to define distinctions between the essential and the desirable; between what is possible and what is beyond its capacities.
That is essentially what Paul is saying, albeit in a cranky, even eccentric, manner. For his pains, he is denounced as a "kook" and "appeaser" and disowned by many in his own party. But US leaders will increasingly place more stress on modesty and limits in a complex and ambiguous world. To fall back on feel-good slogans about a "new American Century" may lead to a painful comeuppance.