Last week, the US Supreme Court heard oral arguments in a GOP-backed effort to repeal campaign finance limits on how much money parties can redirect to individual candidates.

This case could expand the court’s 2010 Citizens United decision, which overturned generations of anti-corruption campaign finance regulation and opened the floodgates of corporate and billionaire political giving.

The Citizens United decision still kept intact decades-old limits on party-coordinated campaign spending, which the Supreme Court upheld in 2001 in the face of another Republican-led effort against campaign finance limits, in part, because they stop donors from simply circumventing individual giving caps by funneling money through parties.