Arizona State University recently released a paper fact-checking various claims being made about immigration. Here's a summary.
Stuff People Get Right:
-Arizonans really do like their tough new law - 64% favor it.
-Arizona really is being peopled by immigrants: about 60% of Arizonans under the age of 7 have immigrant parents.
-The effect of immigrants on the economy really does benefit employers and hurt the least skilled.
Stuff People Get Wrong
-A majority (57%) of Arizonans actually welcome any immigrants who are willing to work and aren't dangerous.
-Anger over immigration probably isn't racist, as it's mostly directed at the federal government and not the immigrants (85% vs. 10%).
-Arizona isn't experiencing an immigrant-driven crime wave; in fact, the US generally is experiencing a record low in crime, and states with lots of immigration in particular have seen the biggest decrease in crime
-Arizona's public services aren't clearly taking a beating from illegal aliens. While many students are the children of illegal immigrants there's no evidence that this is overcrowding the state's schools. Illegal aliens do account for about 1/6th the prison population, but don't account for the explosive growth in that population - tougher sentencing and laws are the cause. Immigrants account for about 6% of hospital spending on treating the un- and under-insured.
-Illegal immigration has only a small net effect on the U.S. economy. The paper doesn't say if this is true of Arizona's economy in specific, though.
Stuff We Just Don't Know
-We don't know exactly how much crime is being committed by illegal immigrants as immigration status is generally not recorded by police.
-We don't know how many illegal immigrants are coming and going. For what it's worth, "experts believe" immigration peaked around 2000 and that it's slowed or stopped since then.
-We don't know the net economic effect. States with high immigration experienced high growth, but the causality could work either way.
[h/t to The New Republic's blog about cities]