There is no single category of evidence in the history of American law that has been subjected to stricter scrutiny by the courts, to greater resistance against admission and to such a widespread reluctance to accept scientific developments in the courtroom than has been the case with polygraph evidence. The cases in which it has been admitted are the exceptional ones, and the vast majority of reported opinions either deny its use with little analysis or employ techniques of exclusion that are not used against other forms of evidence.
The problem with the polygraph test is, the subject taking the test, may actually believe what they are saying is true, yet are wrong. Without some other evidence to present, this case is nothing more than a she said, he said one. It is nothing more than a delaying tactic by the Democrats.