The measure had been adopted in 2006 by the state's voters, and it said judges may not release on bail persons who have "entered or remained in the United States illegally" and were arrested for "serious felony offenses."
Last year, however, the U.S. 9th Circuit Court of Appeals struck down the law and said that the Constitution's protection for liberty applies to all persons in the United States and that people under arrest have a right to an individual hearing on whether they may be released before a trial.
Lawyers for Maricopa County asked the justices to reverse that decision, arguing that immigrants who were in the country illegally were not likely to show up for a trial if they were set free.
But after considering the case for several weeks, the court said it would not hear the appeal.
The American Civil Liberties Union, which had fought Proposition 100, praised the court's action.
"Arizona officials who tried to strip people of a bail hearing and the presumption of innocence have reached the end of the road," said Cecillia Wang, director of the ACLU's Immigrants' Rights Project. "Laws that are driven by fear-mongering rather than facts are bad policy and violate everyone's civil liberties."
According to Wang, the law was in effect for about seven years and probably had an impact on thousands, perhaps tens of thousands, of people.
The law worked to give prosecutors another weapon to force pleas from immigrants in the U.S. illegally, many of whom were deported and were unable to return to this country, she said in an interview with the Los Angeles Times.
In essence, if an immigrant in the U.S. illegally was arrested on any felony charge, the person was held without bail, she said.
"In a lot of these cases, a person would be arrested under Arizona's smuggling laws or they were people working with a false Social Security number and were charged with identity theft," Wang said. "Prosecutors used Prop. 100 to deny bail and get a guilty plea. The sentence would be time served and because it was a felony conviction the person would go into the deportation pipeline."
Wang said she didn't think any of the people denied bail were still awaiting trial.
Maricopa County condemned the high court's refusal to even hear the case. It also defended its argument that the no-bail provision was needed to ensure defendants appeared in court.
"By declining to hear a challenge to the Ninth Circuit's ruling, the high court is effectively permitting a federal appeals court to veto a law enacted to address specific concerns in Arizona," Maricopa County Atty. Bill Montgomery said in a statement.
"First, there is a concern that defendants subject to deportation by the federal government due to their immigration status may be deported when released from state custody on bail and not be present for further proceedings," Montgomery said. "Second, is my own firsthand experience in finding that defendants released on bail for a serious offense are far less likely to show up for court."
Arizona has not fared well in the high court in defense of its immigration laws. Three years ago, the high court blocked the state from enforcing most of a law authorizing its police to question and arrest people who could not show proof of their citizenship.