The NYT offers up a poll showing 51% of Americans say the Arizona law is "about right," and then uses a "woman on the street" interview that greatly qualifies that finding.
“The Arizona law is fine, but the federal government has to step in and come up with something — and they’re not doing it,” said Pat Turkos, 64, a library worker and Republican from Baltimore.
She said: “I don’t think they should be stopped just walking down the street, only if they’re stopped for speeding, for example. I believe everybody has the right to come here, but I think they have to be made legal citizens.”
First of all, even with the recent changes, someone walking down the street can be stopped if it appears they are loitering (or any number of civil offenses). So part of the problem is that the person does not actually understand the law.
Second, despite supporting the law, this person also supports almost an almost entirely open immigration system that makes everyone legal. That seems contradictory, but on the other hand may reflect a distaste less for immigrants per se, but for illegality.
In short, support for the Arizona law tells us very little about the overall views of the general public. Maybe they are hardcore restrictionists, but maybe they just want the federal government to do something rational that eliminates--or at least greatly reduces--the need for anyone to be in the country illegally in the first place.