(CNN) -- Protesters from several states vow to swarm the streets of Phoenix on Saturday to rally against Arizona's controversial immigration law, organizers said.
An estimated 50,000 people are expected to turn out for a five-mile march to the state Capitol starting Saturday morning, said Sarahi Uribe, one of the organizers for the National Day of Action.
The new immigration law allows police officers to check the residency status of anyone who is being investigated for a crime or possible legal infraction if there is reasonable suspicion the person is an illegal resident. Critics, including U.S. Attorney General Eric Holder, have said the law will promote racial profiling.
Supporters of the bill say its aim is only to enforce federal law. However, critics and supporters of the law seem to agree on one point: that the federal government has not done enough to curb illegal immigration.
Salvador Reza is an immigrant activist who opposes the law.
"Arizona has long been a testing ground of failed enforcement immigration polices ... that empower local authorities to racially profile and terrorize the community, all under the guise of federal immigration enforcement," Reza said.
"The federal government helped create his disaster, now it must stop it," he said.
The American Civil Liberties Union is leading a court challenge to the new law. Holder, who met with a delegation of police chiefs from Arizona and elsewhere this week to discuss the law, has given no indication whether the federal government would file a legal challenge.
Uribe on Friday said protesters are arriving in caravans and buses. Sixty related events are scheduled to take place across the nation the same day.
"We are very excited, people are coming in and going around looking for housing and connecting," she said.
In San Francisco, California, opponents of the law gathered Friday morning to launch a caravan of community and labor organizers to Phoenix for the mass protest, group spokeswoman Mariana Viturro told CNN affiliate KTVU.
Black clergy members from the Bay Area were also heading to Phoenix for the rally, Jackie Wright, a spokeswoman for the Northern California Interreligious Conference, told KTVU.
Meanwhile, the San Francisco Giants are hosting a weekend series against the Arizona Diamondbacks, and protesters are calling for fans to boycott games scheduled for Friday night and Saturday, according to KTVU.
CNN's Helena DeMoura contributed to this report.