By Jane O'Brien
BBC News, Washington
One of the political events of 2007 that has had, and will continue to have, a major impact in the US was something that did not happen.
The new measures in Prince William County sparked some protests
A sweeping reform bill failed to pass Congress this summer, leaving communities frustrated over how to deal with the estimated 12 million undocumented immigrants living in the US.
That has led many to take matters into their own hands, enacting tough new laws to tackle illegal immigration.
Some of the toughest measures have been introduced in Virginia's Prince William County.
There, a new resolution allows local police to check the immigration status of anyone they arrest if they suspect them of being in the country illegally.
That person can then be detained and handed over to federal immigration officials for possible deportation.
"Many residents are very upset that people are coming into the country illegally and then demanding rights, demanding that people speak their language, and at the same time, impacting their community," says Prince William's top elected official, Corey Stewart, Chairman of the Board of County Supervisors.
"We have two hospitals in the county, both of which have emergency rooms that are filled with lines of what we believe are mostly illegal immigrants there to receive routine medical care.
"And the reason they go to the emergency medical rooms is they know that under federal law, the hospitals must treat them if the person says it's an emergency, even though it's not.
"I think Prince William County and the problems that we're having with illegal immigration are a microcosm of the country as a whole."
Local newspaper reporter Keith Walker says the issue has dominated the front pages of the Potomac News for several months, with most residents supporting the county measures.
The immigration issue is one that divides many communities
"These are the sort of letters we've been getting here," he says, opening the paper.
"Since when did it become so hard to understand right from wrong?," he reads. "When did people forget that illegal meant unlawful? The pro-illegal groups like to draw no distinction between a legal immigrant and illegal immigrant, but there is a world of difference.
"Legal immigrants respect our country enough to follow its laws. Illegals think they are above reproach and should be rewarded."
But at the Potomac Mills Mall, not everybody doing their holiday shopping is happy.
"I think it's horrible actually," says one young mother. "I think it's a bill that is not being just to the immigrants and they do a lot of work for us, be it construction jobs to working in McDonalds - things that Americans won't do. So I'm very much against it."
Another resident who emigrated legally from the Czech Republic agrees.
"It's awful, really awful," he says. "Maybe illegal immigration is a problem - but you have to be practical.
"Once the people are here, have lived many years here, have families, you cannot just kick them out."
Other regions have taken the opposite approach to illegal immigration, believing that integration is a better way forward.
In Takoma Park, Maryland, the local government has declared the city an "immigration sanctuary".
"People who are not US citizens, whether they are in this country with documentation or not, have full access to all city services," says City Mayor Kathy Porter.
"It also means that our police department does not co-operate with the federal immigration and customs enforcement department in enforcing federal immigration laws."
Ms Porter believes that the federal immigration policy is the responsibility of the federal government alone.
"As a local official, my responsibility is to provide services to my residents," she adds.
"And I believe that having an open policy towards immigrants helps preserve public order because it encourages a relationship of trust between the police department and our immigrant communities."
Advocacy groups say the growing patchwork of state and local legislation is not the solution to America's immigration issue.
Calls have grown for tighter security on the US border with Mexico
Mary Waslin, of the Immigration Policy Centre, says it should be the responsibility of Congress - and that some of the harsher local laws are causing deep division across the country.
"You cannot tell somebody's immigration status simply by looking at them, by their appearance," she says.
"So where these proposals have come up we've seen a great deal of discrimination and racial profiling.
"People assume that certain people are immigrants or assume that they are undocumented immigrants based on their appearance.
"And so what we've seen is that the entire Latino community, for instance, is feeling increasingly under attack, regardless of their immigration status."
Many regions are facing legal challenges to their local immigration laws.
And with Congress unlikely to tackle the crisis for at least another year or more, immigration has become a hot topic among White House contenders.
Finding a new way forward will be one of the most pressing tasks facing the new president.