Not every hiring preference is evidence of discrimination. You can limit the number of applicants by setting parameters—such as considering current employees first.
Recent case: Warren, who is black, applied for a job with the U.S. Forest Service. There were two application avenues: one for current and former federal employees and another for everyone else. Warren fell into the second category.
The Forest Service hired a white woman who had experience as a federal employee. Warren sued, alleging race and sex discrimination.
The 3rd Circuit tossed out his lawsuit. It decided that the Forest Service was free to set up two applicant pools. It could then select an applicant from whichever pool it chose. (Gladden v. Vilsack, No. 11-3001, 3rd Cir., 2012)