The FCC voted on Thursday to remove the cap on TV station ownership in the U.S., delivering a big win to media companies aligned with President Donald Trump and the Republican Party.

Supporters of the cap immediately said they will challenge the FCC’s action in court. They argue that only Congress has the authority to make such a change.

While the legal battle plays out, the rule change will likely mean that big station group owners like Sinclair will buy up more TV stations, furthering a shift from local to national ownership.

Thursday’s party-line vote repealed the national broadcast ownership rule, which bars a single company from reaching more than 39% of U.S. TV households over the public airwaves.