On 20 March 2020, at the onset of the coronavirus pandemic, the Trump administration invoked a World War II-era public health law – contained in Title 42 of the US code – to authorize US border officials to turn away migrants at the US southern border in order to prevent and control the spread of COVID-19 in border facilities.
On 1 April 2022, the Biden administration decided to end such restrictions starting from 23 Mary 2022. Shortly afterwards, 21 Republican-led States filed an action against such latter decision and asked the District Court of Louisiana to issue a temporary restraining order "against any implementation" of the policy's termination before 23 May 2022.
By decision of 25 April 2022, the federal court upheld the plaintiffs’ motion and temporary blocked the Biden administration’s decision. Notably, during the relevant hearing, the Court held that “plaintiff states have demonstrated a likelihood of success on the merits with respect to, at a minimum, their claim that the April 1st termination order was not issued in compliance with the Administrative Procedure Act” and that the termination of the Title 42 suspension orders would have resulted in increased costs and burdens, including increased healthcare costs, injuries which clearly outweighed that of defendant’s.