It was already an incendiary topic: whether to grant illegal immigrants driver's licenses.
To critics, it is an implicit welcome to millions of illegal Latin Americans each year. To many supporters, it's a simple matter of safety: helping thousands of active drivers learn traffic laws.
But now there is another layer in the debate: whether terrorists could slip across the border and apply for licenses, helping them put together an identity that looks authentic.
As a result, the issue of granting drivers' licenses to illegal immigrants - or restricting their access even more - has become one of the hottest topics in states across the country.
At least two bills are pending in Congress that would delineate requirements affecting the use of driver's licenses or ID cards. Legislation is also being debated in a number of states beyond the large immigrant magnets of California and Florida.
"States large and small in every corner of the country are wrestling with the issue of driver's licenses and identification for immigrants and illegals," says Tyler Moran, who tracks the issue for the National Immigration Law Center (NILC). "There remains a deep split in terms of whether states want to restrict or expand access. So the debate has become high profile."
In California, a bill granting driver's licenses to illegals was rescinded in January with the promise by Gov. Arnold Schwarzenegger that a new bill would go forward after key concerns about homeland security were addressed. The issue will probably be back at the forefront of state politics once the current budget wrangling is over.
In the meantime, national observers have switched focus to a first-of-its kind law in Tennessee which took effect July 1. The law is unique in seeking to bridge the divide, analysts say, by conceding key points to both sides. The new law gives a so-called "certificate of driving" to illegal immigrants, but bars them from using the same document for official identification. Thus the certificate seeks to ensure that the holder has mastered the state's motor vehicle laws, but won't allow the individual to board airplanes, buy a gun, or rent a car.
The bill was designed with the Sept. 11 terrorist attacks in mind, since hijackers used driver's licenses as IDs. To distinguish the certificate from existing licenses, the document is printed on purple paper and reads, "For Driving Purposes Only, Not Valid for Identification."
But if the law sought to please both sides, it hasn't necessarily achieved that goal.
No state should give official identity documents to "people we know nothing about," says James Staudenraus of the Federation for American Immigration Reform (FAIR). He complains the law requires only that applicants supply two proofs of Tennessee residency and sign affidavits saying they have no Social Security number. The new law, he says, "clearly undermines public safety, national security, and puts Tennessee law enforcement officers at greater risk."
On the other side, many fear the law does not go far enough to ensure that illegal immigrants won't be arrested for other reasons when stopped for a traffic violation. Immigrant-rights groups say illegals have called to mention their fears of being mistreated by DMV staff or law enforcement.
Many state voters feel conflicted over the issue, concedes Tennessee Rep. Donna Rowland. "We don't know how airports and other states are going to recognize [Tennessee's new card], or private businesses for that matter," she says. "There has been conflicting information from official bodies on how to deal with these answers. It's already creating a problem."
Because of such comments and confusion, some observers say the best answer is for Congress to establish uniform security standards for driver's licenses that all states must comply with.
"If the states can't establish uniform standards, the driver's license will continue to be the massive, gaping hole in national security that aided the 9/11 hijackers," says Dan Stein, executive director of FAIR. "This twilight zone between state and federal sovereignty has created a huge security gap. It is imperative that the federal government step in rather than stay back and watch states like Tennessee and California continue to consider their own bills for their own political and economic reasons."
One bill in Congress would require nonimmigrant aliens to produce a valid nonimmigrant visa when applying for a state driver's license or ID card. The license would expire along with the visa.
One state, South Dakota, has an absolute requirement that drivers have a Social Security number to get a license. Many other states, including New York and Texas, have "lawful presence" requirements. Of the 10 that don't have such requirements, most require an ID issued by an immigrant's home country.
Tom Moore, deputy director of safety for the Tennessee department of safety, says the card is "a document to drive on, nothing more. We are not in the immigration business, we don't enforce immigration laws but rather those of the highway."
In most states, the major point of contention seems to be over what kind of background checks will be required by license holders. A Florida bill was also abandoned when law enforcement raised red flags over background checks.
Sponsors of the California bill say they have addressed such concerns in three, major new ways.
One, applicants will have to find a licensed US citizen to vouch for them. Two, They will have to sign an affidavit acknowledging the document can't be used to purchase firearms, to vote or to serve on a jury. And three, they will need to sign an affidavit pledging they will apply for citizenship at the first opportunity.
"Voters are conflicted," says Edward Headington, spokesman for Gil Cedillo, sponsor of the California bill. "They know immigrants are an important part of the world's fifth-largest economy [California], but then say they don't like it if they are here illegally."