Congress has the authority to establish federal courts; state legislative bodies establish state courts.
This can vary from state to state. Often is is the decision of the district attorney, but opinions on this are changing -- see the related link for more information.
The President has the ability to appoint justices to the Supreme Court (and lower federal courts) with the "advice and consent of the Senate" that share his (or her) ideology. Judicial appointment to lower Article III courts can also be considered a means of influencing the Supreme Court, as the lower courts handle far more cases and have the opportunity to write opinions that have persuasive authority.
The authority to overrule state courts.
Jurisdiction
Yes. You should be sure to have a general power of attorney and/or medical power of attorney.
Constitutional courts
An amicus attorney does not even have to be a practicing attorney. They just have to be appointed by the courts to assist a non contested court case issue.
Congress
Courts that have the authority to be the first courts in which most federal cases are heard are known as district courts. These are the trial courts of the federal judiciary system and are responsible for hearing both civil and criminal cases.
Conflicting authority in a legal case is when two courts are not in agreement. This occurs when two different courts of equal standing disagree on something.
State family court have the authority to terminate parental rights.