The National Association of Immigration Judges represents judges employed by the Executive Office for Immigration Review (EOIR), a component of the Department of Justice (DOJ). Immigration Judges are executive branch employees, and are therefore subject to the supervision of the President of the United States or his designates. Most, if not all, executive branch employees are supervised, reviewed, evaluated, and managed by numerous levels of management. No one in the Executive Branch exercises independent judgement that is not reviewed by another Executive Branch employee, if not the President himself.
Immigration Judges are first supervised by the Chief Immigration Judge, Deputy Chief Immigration Judges, and Assistant Chief Immigration Judges, as well as the Attorney General, in both the exercises of their authority and administratively. Immigration Judges are not independent, like real judges, but neutral, in that they do not represent the Department of Homeland Security (DHS), which brings cases to the EOIR. Aliens may not bring cases independently to the EOIR, but only in response to an action taken against them by DHS.
Now, most attorneys in the DOJ are not unionized, e.g., represented by a bargaining unit in negotiating working conditions and disciplinary action, but not wages, benefits, or other conditions of employment. In Federal unions, pay and benefits are not authorized as those are set by legislation. Represented employees are also prohibited from taking action such as strikes or work slowdowns.