The American Federal Court System is organized by territories, so if you file a federal lawsuit, your case will land on the lap of a subset of federal judges. This means that even with a balanced makeup of Democrats and Republicans judges at the federal level, you can increase your odds of getting your case handled by a judge receptive to your arguments by filing it in a specific town/state.
Conservatives seem to have taken full advantage of this loophole at least since the 2016 Trump administration nominated a bunch of conservative-leaning federal judges in defiance of the unwritten rule to keep the federal courts ideologically balanced.