Steven Camarota of the Center for Immigration Studies, which favors the Arizona law, said today's decision was not unexpected. "The law had a lot of safeguards built into, but ultimately the judge didn't believe that Arizona could implement the law in an unproblematic way. This is strange because it assumes that, but there hadn't been any cases of misuse of the law."
Arizona Senators John McCain and Jon Kyl also expressed disagreement with the court's opinion and called the federal lawsuit against Arizona a "waste of taxpayer resources."
"The Obama Administration should have focused its efforts on working with Congress to provide the necessary resources to support the state in its efforts to act where the Federal government has failed to take responsibility," they said in a statement.
Judge Bolton did not rule today on various requests by lawyers for Arizona and Gov. Brewer to dismiss the various lawsuits against SB 1070. She also still has to decide on other preliminary requests to block parts of the law.
"After a preliminary injunction there is a trial on the permanent injunction," said New York Law School professor Lenni Benson.
The judge "can dissolve it later if, after greater consideration or development of more facts and time to assess the law, the judge thinks the law goes the other way."
The legal process is expected to drag on for months, after which, legal experts say, parties may still appeal parts of the decision they don't like. The debate over SB 1070 could reach the U.S. Supreme Court.
"This is a significant decision, and the litigation, as it proceeds to a final decision...and probable appeal, has potentially historic dimensions," said Hiroshi Motomura of the UCLA School of Law.
"Almost all state and local efforts to address immigration outside the law in this generation have focused on areas of traditional state regulation, such as employment and housing," Motomura said. "SB 1070 much more clearly is a direct attempt to address and regulate immigration itself. This is why the federal government had to take action in this case, in order to maintain its constitutional position as the exclusive authority on who is let into the United States, who must leave, and ultimately, who is or can become an American."
Meanwhile, law enforcement officers across Arizona are preparing to enforce the measures not blocked today.
"We're not engaged in [racial profiling] now in all types of crimes we enforce. So what's the difference whether you enforce another crime, which is the illegal immigration? So we are very comfortable" enforcing the law, Maricopa County Sheriff Joe Arpaio said on "Good Morning America."
Many immigrant families have begun fleeing the state afraid of the new law's impact, and some activists are even encouraging immigrants to check tail lights on their cars, not to travel in large groups, and remove the Catholic rosaries from their rear-view mirrors.
Erika, a 23-year-old undocumented Mexican student living in Mesa, Ariz., since 1998, says her family is relieved with today's court ruling.
"Yesterday I went to bed really depressed," she said. "This morning, knowing this, everything came back. The hope, the faith, knowing that those prayers are really working."