The chairs hold extensive powers: they control the committee's agenda, and so decide how much, if any, time to devote to the consideration of a bill; they act with the power of the committee in disapproving or delaying a bill or a nomination by the president; they manage on the floor of the full Senate the consideration of those bills the committee reports. This last role was particularly important in mid-century, when floor amendments were thought not to be collegial. They also have considerable influence: senators who cooperate with their committee chairs are likely to accomplish more good for their states than those who do not.