Commentator Glenn Beck said one day after his massive rally “for God” in Washington that Barack Obama ” … is a guy who understands the world through liberation theology, which is an oppressor-and-victim. People aren’t recognizing his version of Christianity.”

Is this an appropriate questioning of the president of the United States, or should religion be a private matter?

Given that the United States is the most religious of the liberal democracies in the world, religion matters a great deal in politics. The majority of Americans — 76 percent — identify themselves as Christians. Non-Christians make up 5 percent. About 15 percent have no religious affiliation.

Every American president and vice president was raised in a household with protestant Christian affiliation, aside from former President John F. Kennedy and Vice President Joe Biden who came from Catholic households. President Obama was raised in a family environment that was very diverse and included Islam, no-religion, Catholic and Muslim schools. In various interviews Obama has never answered questions about religion the way, say, a traditional Christian would.

For most of American history, a Catholic had no chance of being elected president because of the fear that the pope and the Vatican would control him. Kennedy had to make a special and very public effort to educate the public that he did not take orders from Rome, and this action was very important for his narrow victory over Richard Nixon in 1961.

There has never been a Jewish president or vice president.

When former Massachusetts Gov. Mitt Romney ran in the Iowa caucuses and primaries for president in 2008, his candidacy was plagued by questions about his Mormon faith. He was never able to convince the largely Christian Republican voter base that Mormonism was “real” Christianity.

Right or wrong religion is a huge part of American society, law, values and, yes, politics.

Liberation theology, which is preached by Obama’s Chicago-based minister, Jeremiah Wright, is a very edgy form of Christianity. In Latin America, Catholic liberation clergy such as the Rev. Camilo Torres actually took up arms against the government and the upper class and fought guerrilla warfare to overthrow the economic system.

It is legitimate to ask if Obama subscribes to this “revolutionary” vision of faith, something the president has dismissed as nonsense? In American politics, religion is not nonsense, and Obama should more clearly and definitively explain what his religious beliefs are and how these translate into his vision of politics and public policy. That’s especially important now that his faith has become an issue and almost 20 percent of Americans believe he is a Muslim.

In America, public opinion is politics, no matter how poorly informed.