The fox designs the hen house.

“The Internal Revenue Service is asking tax lawyers and accountants who create tax shelters and exploit loopholes to take the lead in writing some of its new tax rules. … [Critics] worry that having private lawyers and accountants draft tax rules could allow them to subtly skew them in favor of their clients. ‘It’s not the fox guarding the hen house; it’s the fox designing the hen house,’ said Paul C. Light, a professor of political science at New York University.” Kevin Drum has much more.