It's also become a kind of Rorschach test for how Americans view the place of Islam in U.S. society, and the nation's more-than-two-centuries-old traditions of religious freedom and tolerance.
But are people debating this so-called "Ground Zero Mosque" even armed with the basic facts? Here are some questions and answers:
Q. Why do they call it "the Ground Zero Mosque"?
A. They shouldn't. In fact, there is no such thing as "the Ground Zero Mosque" or - as some GOP pols have started calling it - "the 9/11 mosque." The proposed 13-story, $100 million Islamic center is two blocks - or about two football fields - away from the Ground Zero location attacked nine years ago.
Q. What is Cordoba House and why do they want to do this?
A. The group had been looking to expand. Considered a force for a moderate and peaceful version of Islam, Cordoba's leader, Imam Feisal Abdul Rauf, has praised the lower Manhattan location because it "sends the opposite statement to what happened on 9/11."
Most local leaders - most notably New York Mayor Michael Bloomberg - have supported the proposal from the git-go.
Q. So what happened?
A. A driving force has clearly been a right-wing blogger named Pam Geller, whose site is named "Atlas Shrugs" in honor of her libertarian hero, Ayn Rand. Geller, who has made outlandish claims that President Obama is a secret Muslim, began pounding the drums in May through her group SIOA - Stop Islamization of America. Geller's efforts won headlines in the conservative-leaning New York Post, riled up some 9/11 families and floated into a political outrage-o-sphere populated by the likes of 2012 GOP White House hopefuls Newt Gingrich and Sarah Palin, who then famously took to Twitter to ask "peaceful Muslims" to "pls refudiate" the idea.
Q. But isn't it indeed an affront to 9/11 families and other New Yorkers to have an Islamic center so close to where al Qaeda attacked Manhattan?
A. A poll last week found that 68 percent of Americans (but only 31 percent in Manhattan) oppose the project. But many critics seem eager to conflate the entire Islamic faith - with 1.4 billion adherents worldwide - with the small band of violent extremists.
Although the Imam Rauf has criticized American policy at times, generally speaking Rauf and his anti-militant beliefs are Osama bin Laden's worst nightmare. That is why the administration of President Bush selected him for a Muslim outreach program to travel to Arab nations abroad in 2007.
Rauf reportedly also aided the FBI in counterterrorism efforts in 2003.
Q. But people are really just opposed to this mosque, near Ground Zero, right?
A. Not really - in fact, there have been rising cases of Americans opposing the construction of new mosques from Tennessee to California. Some experts see a link between public anger over the stalled U.S. economy and increasing xenophobia - on the border with Mexico as well as toward Islam.
"The rise of the tea party and the reaction against Obama - I think that's all raising the temperature," said Ihsan Bagby, an associate professor of Islamic studies at the University of Kentucky.
Q. Aren't some politicians exploiting that?
A. You betcha - some conservatives clearly see a chance to burnish their pre-2012 Republican primary credentials with the tea party set, including Gingrich, Palin and a right-drifting Minnesota Gov. Tim Pawlenty.
"They're running against the Muslim president who wasn't born in America," said University of Virginia historian and presidential pundit Larry Sabato, satirically referring to two myths about Obama.
Q. But won't this Islamic center muck up the sacred zone around Ground Zero?
A. That depends on your definition of the word "sacred." The New York Daily News reported this week that the two-block zone around Ground Zero includes establishments like the Pussycat Lounge, a strip club.
Q. And isn't there already a mosque in lower Manhattan?
A. Why, yes, there is. The Masjid Manhattan is little more than four blocks from Ground Zero, and it's been there since 1970, the year before the World Trade Center opened - operating with no controversy whatsoever.