Imagine a room full of Communists who are furiously debating the meaning of Marxist ideas. Shouting and screaming, the Communists would see themselves as deeply divided. But to an outsider, things might look very different: This is a room full of ideologues who all share the same basic view of the world.

In the same vein, people in the United States are struck by what divides Americans. But foreign observers often see, instead, what unites Americans. In Democracy in America, Alexis de Tocqueville wrote that he knew "of no country where there is generally less independence of thought and real freedom of debate than in America. ... The majority has staked out a formidable fence around thought. Inside those limits a writer is free, but woe betide him if he dares to stray beyond them."

Are we really saying that Americans are ideological in the sense that the Soviet and Chinese Communists were ideological? Of course not -- that would be ridiculous. Americans are far more ideological. In other words, liberalism is deeper-rooted and more universally accepted in the United States than communism was across the seas.

The Soviet and Chinese Communists imposed a communist ideology on top of pre-existing nationalist identities. During the 1980s and 1990s, it proved fairly easy for Russians and Chinese to abandon Communism and embrace the free market.



But America's ideology is its identity, and would be incredibly difficult to cast off. Russians without Communism are still Russians. Americans without liberalism have no idea who they are.

America's ideological unity is just as important as any ideological division. As Louis Hartz wrote back in the 1950s: "it is a remarkable force: this fixed, dogmatic liberalism... It is the secret root from which have sprung many of the most puzzling of American cultural phenomena."

Liberal idealism forges the nation's sense of optimism. Henry Kissinger observed that "for other nations, utopia is a blessed past never to be recovered; for Americans it is just beyond the horizon."



At home, the liberal hegemony helps to explain the difficulty that socialists have faced getting a foothold in the United States.



Abroad, the ideology of liberalism transforms America's wars into crusades to spread our values, whether it's saving the world for democracy in World War I, fighting for the "Four Freedoms" in World War II, or building a beacon of liberty in the Middle East by invading Iraq.



Tea Partiers, union organizers, Republicans, Democrats, truthers, birthers -- Americans are a diverse lot. But everyone's looking at the stars. For Alexander Hamilton once said that liberal principles are inscribed in the heavens by the hand of God. We all agree that the celestial constellations should guide our national voyage, even while we vigorously debate the precise images formed by the stellar lights.