Finally, we turned to NumbersUSA, an Arlington-Va.-based nonprofit group that opposes illegal immigration and advocates for limits on legal immigration, because it tracks what the presidential candidates say about immigration. The group’s president, Roy Beck, told us that Romney has expressed support for enacting "attrition by enforcement" policies on a national level such as requiring that businesses use E-Verify. Beck said Romney has not said specific provisions of SB 1070 should be taken as a model for federal immigration laws.

Day laborers, mostly illegal immigrants from Mexico, also had proliferated in other areas of metropolitan Phoenix, including Guadalupe, west Phoenix and Fountain Hills.

But drive by any of those locations now, and only a handful of day laborers are left. And no longer do they rush up to vehicles en masse, waving their hands in a desperate bid to get hired. Now, they are more likely to keep a lower profile, leaning against a tree or sitting on a milk crate.

There are several reasons for the change. Arizona's slumping economy has dried up the demand for day laborers, who typically are hired for yard cleaning, moving, tree cutting, construction and other jobs. Many have left Arizona to look for work in other states, or they have given up and returned to Mexico.

Missouri sheriffs are giving their support to law officers in states along the Mexican border seeking to enforce immigration laws.

The Missouri Sheriffs' Association this week approved a resolution backing states that have approved their own legislation on immigration enforcement. The resolution specifically mentions Arizona, where part of a new law on the subject has been blocked by a federal judge.

The Missouri sheriffs group said Wednesday the resolution was approved by more than 100 members at its annual meeting, with no votes in opposition.