Answer:
1. Federal courts have jurisdiction over cases in which the accusation pertains to a violation of federal law, and also in cases where parties involved in a lawsuit are from different states within the US or if one of the parties is a foreign entity.
An example of the first type would be if police officers or a police department were accused of violating the civil rights of an individual or group. This would be tried in a federal court.
An example of the second type would be if a business owner in one state was sued by someone from another state for breach of contract or for fraudulent business practice.
2. Presidents (in general) will tend to appoint judges who align with their own views on political justice because they don't want their own attempts at leadership blocked by the courts, and also they hope to be able to leave a lasting legacy on nation overall through what they would consider favorable court decisions. Ideally, however, presidents will choose appointees for federal courts and the Supreme Court based on the overall strength of their qualifications, not merely based on political leanings they may seem to have.
3. Once a case reaches the Supreme Court, the The Supreme Court itself decides which cases it will hear.
The Supreme Court is asked to review more than 7,000 cases each year, so it would not be possible for the court to hear and make a decision on every case that is sent to it. The Supreme Court agrees to hear about 100 to 150 cases per year. The vast majority of those cases work their way up to the Supreme Court from lower courts. About two-thirds of the cases come from lower federal court decisions that are appealed for review, and about one-third of the cases are reviewing decisions made by supreme courts of individual states.
There are some cases that can have original jurisdiction at the Supreme Court level -- such as when there is a case between one state government and another or between state governments and the federal government. These are more rare within the overall agenda of the Court.
Explanation:
