The Congress acts through a system of specialized standing committees in both Chambers. The Senate is the most powerful House of Congress, as its approval is required for important federal nominations and for ratification of international treaties. The president's political program needs congressional approval, with the president addressing Congress in January for an annual "state of the union" speech, as well as sending periodic "messages" and "recommendations". The success of a president in carrying out his grassroots program depends on the support of congressional voting, adjusting competencies and public support.