Arizona Gov. Jan Brewer today signed a controversial immigration bill into state law, advancing a politically charged debate that is already having reverberations in Washington.

"Respect for the rule of law means respect for every law," said Brewer, a Republican. "People across America are watching Arizona.

"We in Arizona have been more than patient waiting for Washington to act," Brewer added. "But decades of inaction and misguided policy have created a dangerous and unacceptable situation."

Brewer's decision came just hours after President Obama called the proposal "misguided." At a naturalization ceremony for new U.S. citizens today, Obama pressed Congress to revamp federal immigration policy or face the possibility of "irresponsibility by others."

The law, which will take effect in 90 days, will make it a state crime to be in the country illegally. The measure would require migrants to produce papers verifying their status when asked to do so by a police officer, according to a story in The Arizona Republic.

Debate over the Arizona policy comes as immigration is once again moving to the fore in Washington. Earlier this week, House Speaker Nancy Pelosi, D-Calif., said Congress may take up immigration after it finishes a pending financial regulation bill. "If the Senate is ready with an immigration bill, we don't want anybody holding it up for any reason," she said.

Back in Arizona, Brewer is facing a tough election year, including a contested primary and what the non-partisan Cook Political Report has rated a "toss-up" general election. State Treasurer Dean Martin, who is running against Brewer in the GOP primary, called on her to sign the bill.

State Rep. Russell Pearce, the Republican state lawmaker who sponsored the legislation, said critics of the bill are "against law enforcement, our citizens and the rule of law," according to the Associated Press.

But civil rights and Hispanic groups have condemned the measure, arguing it could lead to profiling. Rep. Luis Gutierrez, D-Ill., a member of the Congressional Hispanic Caucus, said today he will travel to Phoenix to take part in protests planned this weekend.

"Now the national spotlight is focused squarely on Arizona," Gutierrez said in a statement. "People from all over the country are making their way to Phoenix to stand up with and stand up for immigrants and Latinos in the state."

Updated at 5:05 p.m. ET. Brewer's office has posted the governor's full statement here.

Updated at 5:20 p.m. ET. Hundreds of protesters surrounded the Arizona State Capitol and began chanting "shame on you," seconds after Brewer signed the law, The Arizona Republic reports here.

Demonstrators have been camped outside the Capitol since the measure was approved by the state legislature on Monday, according to the Associated Press. Their numbers have grown through the week.

Updated at 5:24 p.m. ET. The Los Angeles-based Mexican American Legal Defense and Educational Fund is already threatening to test the law's constitutionality.

The group "will be pursuing all legal avenues to challenge this law," MALDEF president Thomas Saenz said in a statement. "We have every expectation, based upon judicial precedent and unquestioned constitutional values, that [the law] will be enjoined before it can ever take effect."

Updated at 6:17 p.m. ET. A group of faith leaders is calling the new law a "moral and social sin."

(Posted by John Fritze)