As protests to Arizona's new illegal-immigration law continued Thursday - spurred on by the attendance of music stars Shakira and Linda Ronstadt - the first three lawsuits challenging the law's constitutionality were filed in federal court. Other groups promised their legal challenges would not be far behind.

More threats of boycotts were issued from across the country, while a new poll suggested that just over half of Americans support the law that makes it a state crime to be in the country illegally and requires local police to enforce federal immigration laws.

The Legislature on Thursday also sent changes to the law to the governor.

The Washington, D.C.-based National Coalition of Latino Clergy and Christian Leaders filed a suit in U.S. District Court in downtown Phoenix on Thursday claiming the law is illegal because it usurps federal authority in immigration enforcement and may lead to racial profiling.

Coalition board Chairman Miguel Rivera said his group represents more than 300 churches in Arizona and 30,000 churches in 34 states nationwide.

Arizona Rep. Ben Miranda, D-Phoenix, an attorney, is working with the group on the lawsuit.

"(The group) felt it was urgent for this to be filed immediately because of the economic factors and the human factors," Miranda said.

He said they responded to the law quickly to calm community fears and assure the law never goes into effect.

Two police officers, one from Phoenix and one from Tucson, each filed their own federal lawsuits.

The suit on behalf of Tucson Officer Martin Escobar alleges the new immigration law violates constitutional rights and could hinder police investigations in Hispanic-prevalent areas. The lawsuit also claims it violates federal law because Tucson police and the city have no authority to perform immigration duties.

The lawsuit filed on behalf of Phoenix Officer David Salgado alleges the new immigration law violates his 14th Amendment rights of equal protection under the law. According to the suit, Salgado routinely interacts with individuals who "speak little or no English, and do not have any form of state or federal identification."

Salgado believes the new immigration law puts him between a "rock and a hard place," said his attorney, Stephen Montoya.

"If officers enforce the act, they'll be sued. If they don't enforce the act, they'll be sued," Montoya said.

Also on Thursday, the American Civil Liberties Union of Arizona, the Mexican American Legal Defense and Educational Fund and the National Immigration Law Center confirmed their plans to file a joint lawsuit. Dolores Huerta, sister-in-law of labor activist Cesar Chavez, and musician and Tucson native Linda Ronstadt support the groups' effort.

"This policy of hatred versus Latinos and immigrants cannot continue," Huerta said.

Ronstadt said the new law will undermine the community's trust in law enforcement.

"We don't have to take this lying down," she said. "The Mexican-American community is not going to take this lying down."

Legal representation

Officials with Attorney General Terry Goddard's office said Goddard, the state's chief lawyer, likely would not defend the state in any lawsuits related to the law.

Goddard, who has previously spoken out against the immigration law, has not yet formally bowed out because his office has yet to see the lawsuits.

"(Goddard) will likely not be involved in the litigation because of his position in opposition to the bill," said Deputy Attorney General Greg Stanton.

Stanton said the office will provide lawyers to represent the state, although Paul Senseman, spokesman for Gov. Jan Brewer, said Brewer is empowered to select someone if she doesn't like the office's appointment.

However, the Attorney General's Office will likely challenge any effort to usurp its authority, Stanton said

County opinions

Interim Maricopa County Attorney Rick Romley vowed to uphold the law, but he plans to have his staff do an analysis to make sure that all parts of it can pass constitutional muster.

He worried, for example, about provisions enabling law enforcement to hold people indefinitely pending confirmation of immigration status. State and federal law set clear limits on the time a person can be held without filing charges.

"We have rules that if you don't charge a person within a certain period of time, they're out," he said.

His deputy Jim Keppel, who resigned from the Superior Court bench to assist Romley, added his concern over civil lawsuits that could be filed against police officers who fail to attempt to determine the status of illegal immigrants.

"What other kind of crime do we put that kind of potential civil liability on a police officer if he or she doesn't arrest somebody under certain circumstances, if you don't arrest somebody?" Keppel asked. "You've got murders, aggravated assaults, sex crimes where there's no civil liability for a police officer who doesn't arrest somebody."

Maricopa County Sheriff Joe Arpaio urged people to temper their reactions to the law until they see how it's enforced.

Police officers and law enforcement "won't go around racial profiling and grabbing people because of the color of their skin," he said. "Let's not judge everybody right now before the law has been enforced."

Law changes

The Legislature on Thursday approved several changes to the immigration law. They now go to the governor for consideration.

If Brewer supports them, they would go into effect along with the new law July 29, barring any legal stays.

The law requires officers making "lawful contact" with an individual to make a reasonable attempt "when practicable" to determine the immigration status of the individual if they have reasonable suspicion that the individual is in the U.S. illegally. Officers do not have to do so "if the determination may hinder or obstruct an investigation."

In an effort to address concerns over how crime victims or witnesses would be treated, the phrase "lawful contact" would be changed to "lawful stop, detention or arrest."

The word "solely" would be eliminated from the sentence "A law enforcement official or agency . . . may not solely consider race, color or national origin . . . " in establishing reasonable suspicion that someone is in the country illegally.

Pearce said the intent is to clarify that "this bill prohibits racial profiling in any form." Bill opponents had argued the word "solely" allowed officers to base their reasonable suspicion on race and color as long as it wasn't just one of them.

Rep. Kyrsten Sinema, D-Phoenix, said those two changes help clarify the bill and lighten its impact somewhat. But she called a third change "frightening."

That change clarifies that a police officer responding to city-ordinance violations also would be required to determine the immigration status of an individual they have reasonable suspicion of being in the country illegally. Ordinance violations vary by municipality, but could include things like loud parties, barking dogs or too many renters, Sinema said.

Senseman said Sinema is mischaracterizing the changes. He said the amendments do not make the bill harsher, but clarify the original intent of the legislation.

"We totally disagree that this is new or an expansion," Senseman said. "What we were always talking about and always have been talking about are things like discharging firearms, alcoholic beverages in the park or speeding in a school zone."

Senseman said that is possible that "in extreme incidents" there could be a situation where police are called out on an ordinance violation and in the course of investigation question immigration status.

But, he said, those situations are "rare" and "still represent legal violations."

The Governor's Office believes the new language, combined with the original wording of the bill, gives the law "maximum ability to withstand legal scrutiny."

"There have been a number of distortions about what this law encapsulates," Senseman said. "This language only boosts the legal defense."

Public sentiment

A new Gallup poll indicates that more than three-quarters of Americans have some familiarity with Arizona's tough new immigration law, and of those, just over half support it.

The survey, released Thursday, indicates that 51 percent of Americans, who had heard of Senate Bill 1070, favor it. Thirty-nine percent of respondents oppose it, according to the survey.

Support appears to be strongest among Republicans, according to the poll.

About 75 percent of GOP-affiliated respondents who had "heard or read a great deal, a fair amount or not much" about the bill indicated that they approved of SB1070, compared to half of the independents polled and 34 percent of Democrats surveyed.

The Gallup survey, conducted by telephone on Tuesday and Wednesday, polled 1,013 adults nationwide. It has a margin of error of plus or minus 4.5 percentage points, with a 95 percent confidence level.

Star power

Latin pop star Shakira visited Arizona on Thursday to speak out against the new law.

"I'm in opposition to this law because it is a violation of human and civil rights," Shakira said. "It goes against all human dignity, against the principles of most Americans I know."

Shakira met privately with Phoenix Mayor Phil Gordon, Vice Mayor Michael Nowakowski, Police Chief Jack Harris and other city officials to raise concerns about the law.

She argued that Hispanic immigrants have generated economic growth for decades in this country.

"Immigrants forged this country," she said. "They came to this country wanting to work hard. They work long hours."

Gordon said he had created a fund called Arizonans for Common Sense to raise private money for a lawsuit he intends to bring on behalf of the city to block the law from taking effect. Shakira said she would support Gordon in his legal efforts.

Shakira later visited the CPLC Carl Hayden Youth Community Center in Phoenix.

Victor Gonzalez of El Mirage was one of the people invited to meet and speak to her. He predicted the new law would be overturned by the courts.

"It's not going to happen," he said. "I'm sure the guys who wrote the Constitution would be laughing if they were here today."

Reporters Michael Kiefer, Casey Newton, JJ Hensley, Lily Leung and Glen Creno contributed to this article.