if the Electoral College fails to select a president or vice-president, they have the power to select them. They also serve as the jury and prosecution in impeachment trials.
The judicial branch is made up of the Supreme Court and all of the lower federal courts. The most significant power of the judicial branch is that of judicial review. Judicial review states they have the power to decide whether laws passed by Congress are constitutional, determine if treaties negotiated by the President are constitutional, determine if the methods by which the President in enforcing the law are allowable by the constitutional, and determine if laws passed by states are constitutional. They also interpret what laws actually state and mean. Also, in the case of an impeachment trial, the Chief Justice presides over it.
The executive branch is the President, the cabinet, and all federal agencies and their heads. The President is the head and one who deals with foreign matters with other countries. The main roles in the executive branch are the Chief Executive, Chief Diplomat, Commander-in-Chief of Armed Forces, and the Chief of State. Collectively they issue executive orders enforcing the laws passed by Congress, act as the head of the federal bureaucracy and all federal agencies, nominate judges, and appoint government officials. This branch is also in charge of the military. In the case of a crisis they tell the military whether or not to respond and how to respond. Also if the President does not like a law or feels it is not necessary or right, he has the power to veto it. The President also has the power to pardon criminals for federal crimes, except in cases of impeachment.