WASHINGTON (AP) — The US Supreme Court on Monday said it won't hear a challenge to Alabama's ban on the transfer of campaign contributions between political action committees.

The justices left in place a lower court ruling that said the 2010 law does not unconstitutionally restrict political speech.

The Alabama Democratic Conference, one of the state's oldest predominantly African-American political organizations sued state officials over a portion of the law that prohibited ADC's PAC from getting money from other PACs to use for voter communication programs and to get voters to the polls. The ADC previously received about half its money from PACs operated by the Alabama Education Association, the Alabama Trial Lawyers Association, the state Democratic Party and others.

The 11th U.S. Circuit Court of Appeals ruled the 2010 law is not an unconstitutional prohibition on free political speech. The court said Alabama had a sufficient interest in trying to prevent corruption to justify the restriction on political activity.

The Alabama Legislature passed the PAC-to-PAC ban in 2010 in order to restrict donors' ability to hide contributions by shuffling the money through multiple political action committees.