Before leading the way for other states to pursue immigration laws, Arizona passed a ban on human smuggling in 2005.
It has led to more than 2,100 arrests.
It also has drawn criticism for a tactic in which people who pay to be sneaked into the country are charged as conspirators to the crime.
A lawsuit that seeks to bar such conspiracy prosecutions is intensifying.
Lawyers defending the tactic recently asked a judge to throw out the case, while immigrant rights advocates seek class-action status that would let any person charged with conspiracy under the smuggling law to join the case.
Opponents say the law was intended for smugglers, not their customers.
Attorneys defending the conspiracy prosecutions say tactic doesn't conflict with federal law.
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