Which has quickly created a bizarre political phenomenon. All of a sudden, Merrill says, there is a large percentage of the voting public bucking the opinion of nearly every public official they put into office by voting for a proposition that, most everybody admits, will have little impact on illegal immigration.
"The people we're polling are saying it's almost a purely symbolic vote," he says. "It's people in the middle feeling that the elite aren't doing anything because they want the cheap labor. So they're sending a message. It's not about voting for a proposition that fixes something. It's just about sending a message to politicians that the people want something done about immigration."
And, very likely, Prop 200 sentiment is having an effect that its generally right-wing proponents didn't intend. Some experts say it might well politically energize the burgeoning Hispanic community in the Valley, which approaches 30 percent of the population but a far lower percentage of the voting public.
Proposition 200 was couched, at least overtly, on a simple premise: Illegal immigration is very bad for the economics of Arizona.
The proposition was primarily crafted and financed by outside anti-immigration groups who believe that illegal immigration is a huge financial burden on U.S. citizens. Arizona is, essentially, a beachhead for pushing much tougher federal immigration laws.
Steve Camarota, director of research for the Center for Immigration Studies in Washington, D.C., finished in August one of the most comprehensive studies on the cost of illegal immigration in the last decade.
Even he admits, though, that it's still far short of definitive. And because of Arizona's unique economy, his national findings, he says, may not reflect exactly what's happening here.
"We know very little about impacts on the state level," Camarota tells New Times. "Besides that, Arizona's relationship with Mexican immigrants is different than that of most states."
Prop 200 supporters such as Pearce say that illegal immigrants cost Arizonans $1.4 billion a year, a number based on research by the Federation for Immigration Reform, a primary backer of the legislation.
The odds of that figure being close to correct are low. Pearce believes the number is "far too conservative," while several researchers interviewed for this article believe it's far too high -- if there's even any cost at all.
"Those numbers are flawed," says UC-San Diego's Cornelius, "because they are based on a series of assumptions that just aren't true. For one, that study attributes to illegal immigrants costs that would accrue anyway. It throws in fire and police costs acting like we'd fire a bunch of firemen and police officers once illegal immigrants disappeared. This doesn't fit with reality."
More important, Cornelius points out, "most studies don't try to look at the benefits. Especially in Arizona, that's something you must consider."
He says these are the hard-to-quantify benefits of the children and grandchildren of immigrants often attaining higher levels of schooling and pay than their ancestors.
Camarota's study, based on the methodology of a landmark 1997 National Research Council study, does, however, reach some conclusions based on fairly reliable federal data.
Among the findings:
Houses headed by illegal immigrants cost the federal government $26.3 billion in services, while illegal immigrants pay in $16 billion in taxes. That's a net federal loss of $10.3 billion, or $2,700 per illegal immigrant.
Most of the costs are because of immigrants' American-born children, who are awarded U.S. citizenship at birth. (Thus, Camarota points out, efforts such as Prop 200 to block illegals from government programs will have little effect because their children who are citizens still will be able to gain access to the programs.)
On average, the costs that illegal households impose on federal coffers are less than half that of other households (an average legal household costs the government $15,101 a year). But the tax payments of illegals are only a quarter that of an average legal household, which pays in $15,099.
Here's the intriguing part:
If illegal aliens were given amnesty, a plan that has some support in both parties, the cost to taxpayers per household for the about eight million newly legalized citizens would nearly triple, from $2,700 to $7,700, for a total net cost of $29 billion.
Costs would increase dramatically, Camarota says, because unskilled immigrants with legal status -- what most illegal aliens would become -- can access government programs but still would tend to make very modest tax payments. Although legalization would increase average tax payments by 77 percent, the study predicts, average costs would rise by 118 percent.