I can't quote you chapter and verse, but I have seen many GAO reports that firmly support a liberal slant.
They may be cold analytical engineers, but I guess the questions that produce the reports I refer to, are coldy calculated as well.
Coming from politicians looking to back up their own unsupported and outragous claims, the questions would assume the answer. The GAO staff can do no more than dig out the data and try to respond to the question.