A number of district courts have decided that they have the mandamus authority over immigration petition delay, such as N. D of Texas, ND of Clifornia, WD of Pennsylvia, WD of Oklahoma, etc.
Other courts firmly believe the opposite, such as WD of Texas.
A recent mandamus case has been brought to circuit court, which has never happen before. The circuit court opinion will serve as direction for most if not all district courts.
In many district courts, where a previous opinion had not been issued, judges are withholding this type of case to see the further development in the circuit court.