A federal judge agreed with them, but the 4th U.S. Court of Appeals in Richmond, Va., overturned that decision. The Supreme Court's 2010 Citizens United decision struck down a prohibition against corporate spending on campaign activities by independent groups but left untouched the ban on direct contributions to candidates.
The judge said independent expenditures and direct contributions were both political speech, but the appeals court said they must be regulated differently.
The justices will not review that decision.
This comes one week after the justices decided to hear a challenge to limits on how much an individual can give to political campaigns. In that case, an Alabama man argues that it's unconstitutional to stop a donor from giving more than $46,200 to political candidates and $70,800 to political committees and PACs.
Shaun McCutcheon says he accepts that he can only give $2,500 to a single candidate but says he should be able to give that amount to as many GOP candidates as he wants.
The justices will hear that case later this year.