Although it’s technically tomorrow (September 17), today people around the United States will observe Constitution Day, a federal holiday created in 2004 to commemorate the adoption of the U.S. Constitution and those who have, by birth or naturalization, become United States citizens.  The day provides a good opportunity to reflect on how Americans think about what it means to be a U.S. citizen, and how Constitutional values inform our political debates and everyday life.

Despite the fact that the phrase itself never appears in the Constitution, one barometer for how Americans view the Constitution is their support for strict separation of church and state.  This principle is based on the Establishment Clause of the First Amendment to the Constitution, which declares, “Congress shall make no law respecting an establishment of religion.”

In research conducted by the Public Religion Research Institute for our recent report, “What It Means to be American: Attitudes Toward Increasing Diversity in America Ten Years After 9/11,” we discovered that while a solid majority (66%) of Americans agree that we should maintain a strict separation of church and state, these numbers change according to religious affiliation and political identity.  For example,

• Forty-seven percent of Democrats say that they strongly agree with strict separation of church and state, compared to 23% of Republicans.
• Among white evangelicals, only a slim majority – 55% – agree with strict separation of church and state, compared to 74% of affiliated non-Christians and 77% of the unaffiliated..

Despite these disparities, our research also showed that Americans – and especially Republicans – seem increasingly anxious about the possibility of the establishment of Islamic law in America’s courtrooms.  While the general public still rejects the idea that American Muslims ultimately want to establish Shari’a law as the law of the land in the U.S. (61 percent disagree, 30 percent agree), over the last 8 months agreement with this question has increased by 7 points, from 23 percent in February 2011 to 30 percent today.

What does all of this say about Americans’ attitudes toward the Constitution, 224 years after the historic document’s signing?  Share your thoughts in the comments section.  For more resources on Constitution Day, check out the First Amendment Center’s website.