What was the calhoun doctrine?

he pressed for states rights in the case of slavery.
he wanted states to have the right to nullify national laws.
he tried to enforce national laws over states rights.
he supported the increased tariffs to promote industries in his home state.

Which of the following are characteristics of effective government leaders? select all that apply : has accumulated enough wealth to operate the government : willingness to accept responsibility : keep a government strong and active : has be a successful in the entertainment field : act as a final point of authority