Liberal groups that are challenging President Donald Trump‘s agenda are exploring an expanded use of class action lawsuits now that the Supreme Court has slapped down judges’ reliance on universal injunctions.

In a lengthy opinion handed down last week, a majority of the justices said district courts likely lack the power to issue sweeping blockades of executive actions through universal injunctions. But the justices left open the door for litigants to pursue class action lawsuits, and some, including those fighting Trump’s birthright citizenship order, are already pushing for class certification to achieve the same type of widespread relief from Trump’s policies.