If the independent agency exercises any type of executive powers such as imposition or enforcement (and most of them do), Congress can not participate in the process of habitual dismissal of the commissioners. Constitutionally, Congress can only participate directly in impeachment proceedings. The Congress may, however, pass statutes that limit the circumstances under which the President may dismiss the commissioners of the independent agencies. Members of Congress can not serve as commissioners on independent agencies that hold executive powers, nor can Congress appoint commissioners, the Constitution Appointment Clause confers that power on the President. The Senate can participate, however, in appointments through "advice and consent", which occurs through confirmation hearings and votes on candidates of the President.