The Fourth of July is the birthday of American exceptionalism — originally, the idea cherished by the nation's Revolutionary founders that the practice of liberty, equality and democracy in these United States would kindle hope in a world downtrodden by every form of despotism, hierarchy and oppression.

Independence Day marked the determination of a new and diverse people to throw off the old yoke of hereditary rule, with all its attendant traditions of social and economic stratification. The founders believed that America would inspire other nations as an ally and friend, rather than dominate them by force of arms or money. They did not regard their weak new republic as intrinsically superior or chosen to rule the world by God — but argued instead that the ideals of popular sovereignty and constitutional freedom represented the natural rights and the future of humanity everywhere.

So July 4 is a holiday whose meaning still resonates, despite centuries of contradictory history and circumstance. And it ought to be a day for remembering, as I've long argued, that liberalism is as patriotic as apple pie.

But it is also worth noting that the form of American exceptionalism most loudly promoted today is encrusted with unwholesome propaganda. As articulated by the great thinkers of the Republican right, from George W. Bush to Newt Gingrich and Mitt Romney, it is transformed into an aggressive nationalism, a disdain for world opinion and an ostentatious piety that would have repelled the intellectual leaders of the founding generation.

Republican braying about American exceptionalism sounds especially fraudulent in a season when their party is preparing to nominate an unabashed plutocrat for the presidency. By corrupting the U.S. political system with dark money and corporate personhood, their Supreme Court justices, their congressional leaders and now their presidential candidate would impose an aristocracy of wealth just as corrupt and unaccountable as any that existed in old Europe.

That is why ordinary citizens are now so infuriated by super PACs — and so suspicious of Romney's Wall Street career and his Swiss and Cayman Island accounts. There is nothing exceptional about the political influence of dubiously acquired wealth, which is now commonplace across the world, from China to Russia to Mexico to Washington, D.C.

How is American exceptionalism defined today? It would be hard to find a more potent example of what marks this country as truly great, even now, after the myriad abuses and errors of the past, than the ascent of Barack Obama to the White House. Out of a partisan (and sometimes racial) myopia that has very little to do with the president's actual flaws, the Republican right is largely unable to concede that simple fact. Instead, its activists and leaders remain preoccupied with demonstrating Obama's illegitimacy, by slanders about his birth and ideology, for the office that he attained.

If America remains exceptional, it is thanks to the president and the hopeful citizens who elected him — and very much despite his partisan adversaries, those most pious, most misguided exponents of American exceptionalism.