President has no power to refuse to spend appropriated funds when Congress has expressly mandated that they be spent.
Congress can require state courts to hear causes of action based upon federal statutes.
State governments or agencies are not citizens of a state for the purpose of federal diversity jurisdiction.
A private citizen cannot sue a state in a federal court.
A private citizen can challenge the constitutionality of a state statute in a federal court by suing a state officer to enjoin the enforcement of the statute on the ground that it is unconstitutional.
Political subdivisions of a state can be sued by citizens in federal court because they do not enjoy the protection afforded a state under the Eleventh Amendment.
A person has standing by virtue of being a taxpayer only to challenge legislation authorizing expenditures on the basis that those expenditures contravene specific constitutional limitations on the spending power. The only specific constitutional limitation on the spending power ever found has been through the Establishment Clause of the First Amendment.
Only the president has the right to appoint officers of the United States, and an attempted appointment by Congress or by members thereof is unconstitutional.
Congress has power under the Fourteenth Amendment only to reach state action (or action accomplished under the color of state law) that abrogates the rights guaranteed by that amendment.
Congress has power under the Fifteenth Amendment to directly regulate voting procedures in the states for the purpose of eradicating procedures that affect the rights of minorities to vote or to have their vote counted.
Congress has the power to investigate and subpoena witnesses for the purpose of obtaining information with respect to potential legislation that it might pass.
An individual can successfully defend against a contempt-of-Congress charge for failing to answer a question from a congressional committee only if the witness can show that the subject matter of the questioning was beyond the power of Congress to pass potential legislation or beyond the scope of the power delegated by Congress to that committee
Courts cannot decide ecclesiastical questions management or property.
The President has power to settle claims of U.S. citizens against foreign government through an executive agreement.