Is U.S. District Judge Susan Bolton’s blocking of key portions of the Arizona immigration law as bad as it looks for supporters? The Wall Street Journal’s legal blog talked to Peter Spiro, an immigration law expert at Temple University:

Spiro said that while the injunction will likely be appealed by Arizona, the state will probably have a hard time getting the Ninth Circuit to overturn it. “There’s a pretty high threshold on overturning injunctions on appeal,” he said. “I think this injunction will probably hold up.”

With the injunction in place, the case will likely head to trial. In the courtroom, Spiro doesn’t necessarily expect Arizona and its law to fare much better. “Here you’re dealing with more questions of law than questions of fact, and it’s hard to imagine what Arizona would come up with that would lead Bolton to change her mind.” Spiro anticipates that the most controversial parts of the law will be struck down, and that such a ruling will likely be upheld on appeal.

Spiro says, however, that the ruling itself – and even if it’s upheld down the line – doesn’t mean the states are totally disempowered with respect to undertaking action related to undocumented workers.

Spiro expects to see laws passed in states that require employers to verify the status of employees. “This is where you’re going to see continuing activity at the state level,” he says. A challenge to Arizona’s requirement that employers use the so-called federal E-Verify database to authorize the legal status of their workers was shot down by the Ninth Circuit. The Supreme Court in June announced it would hear the case next term. Spiro expects the Supreme Court to follow the Ninth Circuit’s lead and uphold the law.

So what’s the difference, we asked Spiro, between the E-Verify law and the law struck down today? “SB 1070 really overstepped the line by criminalizing undocumented status in a way that was only technically consistent with federal law,” he said.

I have a question: “Undocumented” is a euphemism for illegal, right? Isn’t it already illegal to be an illegal? Spiro does indicate that, though the law in his opinion (and, more important, Bolton’s) overreached, states still retain some methods of controlling immigration-just lots weaker than supporters of the Arizona law hoped.

 The whole question would be moot, of course, if the federal government did its job and secured the borders. Don’t hold your breath.