(CNN) -- Alabama lawmakers passed a new bill Wednesday aimed at improving the state's controversial immigration law, but critics said the new measure might make things worse.
Demonstrators protested outside the chambers of the Alabama state House and Senate. Seven of them were arrested, said Justin Cox, staff attorney with the ACLU Immigrants Rights Project.
The Southern Poverty Law Center's legal director was among those arrested, said Marion Steinfels, a representative of the organization.
Police could not be immediately reached for comment.
The center is one of the plaintiffs in a federal lawsuit against Alabama's immigration law.
The new immigration bill, known as HB 658, was approved by the state House and Senate Wednesday.
The state's governor will have the final say, with the power to sign the bill into law or veto it.
"We will conduct a final review of the legislation as passed and make a final decision from there," said Jeremy King, a spokesman for Gov. Robert Bentley. "Governor Bentley's goal is to emerge with an immigration bill that is simplified, clarified, more effective, and more enforceable."
Alabama Sen. Dick Brewbaker told CNN that the new bill addresses unintended consequences of the state's immigration law, including clarifying the types of documents that can serve as a form of official identification.
It does not address parts of the law that are at issue in federal courts, he said.
Critics say parts of the new measure would be even harsher than last year's immigration law, which is known as the toughest in the nation.
"The new bill preserves most of the law while adding several positions that make it even more dangerous," the Alabama Coalition for Immigrant Justice said in a statement.
Cox, of the ACLU, said the biggest problem of the new bill was the requirement that the Alabama Department of Homeland Security post online the names of illegal immigrants that appear in state courts.
The coalition said that provision "amounts to a 'scarlet letter' provision likely to lead to harassment and vigilantism."
The new measure also includes a provision that allows someone to be detained for up to 48 hours while authorities determine their immigration status.
"Alabama took a step backward in approving this ill-conceived measure," said Olivia Turner, executive director of the ACLU of Alabama. "Lawmakers were deaf to the concerns of many residents, business owners and police who realize this law is a bad idea. Alabama will continue to pay a severe price for a law that is almost impossible to enforce properly and blatantly unconstitutional."
House lawmakers voted 68-37 in favor of the Senate's version of the bill Wednesday night.
Before the vote, several representatives appeared skeptical about the Senate version of the bill. House lawmakers approved a different version of the bill last month.
Rep. Napoleon Bracy Jr. criticized senators for the proposal, calling it "a totally different bill that no one has had a chance to read that's full of unintended consequences."
Other lawmakers worried that the measure would negatively affect the state's economy, and expressed concerns about racial profiling.
But lawmakers backing the bill said it protects the state's residents and helps its economy.
Alabama's existing law, known as HB 56, has several provisions, including one requiring police who make lawful traffic stops or arrests to try to determine the immigration status of anyone they suspect might be in the country illegally.
A federal appeals court has blocked some components, however, including one requiring Alabama officials to check the immigration status of children in public schools.
The Alabama law is one of a number of several state laws aiming to crack down on illegal immigration, and has become part of a nationwide skirmish between state federal officials over who controls immigration enforcement.
Last month, the U.S. Supreme Court heard arguments over Arizona's similar immigration measure. A ruling could come in late June, just before the justices recess for the summer.
CNN's Dave Alsup contributed to this report.