And that the imam who's being branded an extremist has been valued by both Republican and Democratic administrations as a moderate face of the faith.
Even so, the project stirs complicated emotions, and Imam Feisal Abdul Rauf is a complex figure who defies easy categorization in the American Muslim world.
He's devoted much of his career to working closely with Christians, Jews and secular leaders to advance interfaith understanding. He's scolded his own religion for being in some ways in the "Dark Ages." Yet he's also accused the U.S. of spilling more innocent blood than al Qaeda, the terrorist network that turned the World Trade Center, part of the Pentagon and four hijacked airplanes to apocalyptic rubble.
Many Republicans and some Democrats say the proposed $100 million Islamic cultural center and mosque should be built elsewhere, where there is no possible association with New York's ground zero. Far more than a local zoning issue, the matter has seized congressional campaigns, put President Barack Obama and his party on the spot -- divided families of the Sept. 11, 2001, victims, caught the attention of Muslims abroad and threatened to blur distinctions between mainstream Islam in the U.S. and its radical elements.
A look at some of the claims and how they compare with the known facts:
"The folks who want to build this mosque - who are really radical Islamists who want to triumphally prove that they can build a mosque right next to a place where 3,000 Americans were killed by radical Islamists - those folks don't have any interest in reaching out to the community. They're trying to make a case about supremacy." - Former House Speaker Newt Gingrich, a potential 2012 presidential candidate.
Some of the Muslim leaders associated with the mosque "are clearly terrorist sympathizers." - Kevin Calvey, a Republican running for Congress in Oklahoma.
"This radical is a terrible choice to be one of the faces of our country overseas." - Statement by GOP Reps. Ileana Ros-Lehtinen of Florida and Peter King of New York.
No one has established a link between the cleric and radicals. New York Police Department spokesman Paul Browne said, "We've identified no law enforcement issues related to the proposed mosque."
Ros-Lehtinen and King were referring to the State Department's plan, predating the mosque debate, to send Rauf on another religious outreach trip to the Middle East as part of his "long-term relationship" with U.S. officials in the Bush and Obama administrations. The State Department said Wednesday it will pay him $3,000 for a trip costing the government $16,000.
Rauf counts former Secretary of State Madeleine Albright from the Clinton administration as a friend and appeared at events overseas or meetings in Washington with former President George W. Bush's secretary of state, Condoleezza Rice, and Bush adviser Karen Hughes.
He has denounced the terrorist attacks and suicide bombing as anti-Islamic and has criticized Muslim nationalism. But he's made provocative statements about America, too, calling it an "accessory" to the 9/11 attacks and attributing the deaths of hundreds of thousands of Iraqi children to the U.S.-led sanctions in the years before the invasion.
In a July 2005 speech at the Bob Hawke Prime Ministerial Center in Adelaide, Australia, Rauf said, according to the center's transcript:
"We tend to forget, in the West, that the United States has more Muslim blood on its hands than al Qaeda has on its hands of innocent non-Muslims."
While calling terrorism unjustified, he said the U.S. has supported authoritarian regimes with heinous human rights records and, faced with that, "how else do people get attention?"
In the same address, he spoke of prospects for peace between Palestinians and the Israelis - who he said "have moved beyond Zionism" - and of a love-your-neighbor ethic uniting all religions.
"Mr. President, ground zero is the wrong place for a mosque." - Rick Scott, Republican candidate for Florida governor.
"Nazis don't have the right to put up a sign next to the Holocaust Museum in Washington. We would never accept the Japanese putting up a site next to Pearl Harbor. There's no reason for us to accept a mosque next to the World Trade Center." - Gingrich.
"Just a block or two away from 9/11." - Former Alaska Gov. Sarah Palin, another 2012 GOP presidential prospect.
No mosque is going up at ground zero. The center would be established at 45-51 Park Place, just over two blocks from the northern edge of the sprawling, 16-acre World Trade Center site. Its location is roughly half a dozen normal lower Manhattan blocks from the site of the North Tower, the nearer of the two destroyed in the attacks.
The center's location, in a former Burlington Coat Factory store, is already used by the cleric for worship, drawing a spillover from the imam's former main place for prayers, the al-Farah mosque. That mosque, at 245 West Broadway, is about a dozen blocks north of the World Trade Center grounds.
Another, the Manhattan Mosque, stands five blocks from the northeast corner of the World Trade Center site.
To be sure, the center's association with 9/11 is intentional and its location is no geographic coincidence. The building was damaged in the Sept. 11 attacks and the center's planners say they want the center to stand as a statement against terrorism.
"There should be no mosque near ground zero in New York so long as there are no churches or synagogues in Saudi Arabia. ... America is experiencing an Islamist cultural-political offensive designed to undermine and destroy our civilization." - Gingrich.
"This religion's plan is to destroy our way of life. ... If we have to let them build it, make them build it nine stories underground, so we can walk above it as citizens and Christians." - Ron McNeil, a House GOP candidate in the Florida Panhandle, in an exchange reported by The News Herald in Panama City.
Such opinions are shared by some Americans, while others are more reluctant to paint the religion with a broad brush and more welcoming of the faith in this country. Bush, himself, while criticized at the time for stirring suspicions about American Muslims, traveled to a Washington mosque less than a week after the attacks to declare that terrorism is "not what Islam is all about. Islam is peace."
In any event, the U.S. armed forces field Muslim troops and make accommodations for them. The Pentagon opened an interfaith chapel in November 2002 close to the area where hijacked American Airlines Flight 77 slammed into the building, killing 184 people.
Muslims gather there for a daily prayer service Monday through Thursday and hold a weekly worship service on Fridays, drawing no complaints. Similar but separate services are provided for other faiths.