One certainly hopes this is not true. Political litmus testing for IJs could be disastrous for certain types of asylum cases. Immigration Judges assert wide discretion interpreting regulations such as those allowing exceptions to the one-year filing deadline for asylum applicants, and determinations of good moral character of such applicants. Furthermore, the Board of Immigration Appeals (already considered by many immigration practitioners to have been brought into line by then-Attorney General Ashcroft), which has authority to review decisions by the IJs, often does no more than rubber-stamp them. It is difficult to imagine any legitimate justification for stacking the Immigration Court with ideologues committed to a certain agenda.
Excerpt from Legal Times continued here:

The shift in the method of hiring immigration judges began late in Ashcroft’s tenure. At some point members of his staff realized that EOIR had long been appointing at least some immigration judges without open competition. Hearing of this, Susan Richmond Johnson, one of Ashcroft’s closest advisers, remembers thinking, “Why are we not using it? It’s an authority of the attorney general.”
Ashcroft’s deputies, who by this time included Sampson, turned to the Office of Legal Counsel for advice. According to a statement released May 25 by Goodling’s attorneys, the then-head of that office, Daniel Levin, advised Sampson that immigration judges “were not subject to civil service rules applicable to other career positions.”