US Constitution

These examples are best given by a description of the courts rulings in cases.

Marbury VS Madison (1803) made several points and is a good case to make a few points about:

"The question, whether and act, repugnant to the constitution, can become the law of the land, is a question deeply interesting to the United States; but happily, not of an intricacy proportioned to its interest. It seems only necessary to recognize certain principles, supposed to have been long and well established, to decide it. Certainly all those who have framed written constitutions contemplate them as forming the fundamental and paramount law of the nation, and consequently, the theory of every such government must be, that an act of the legislature repugnant to the constitution, is void. Thus, the particular phraseology of the constitution of the United Stats confirms and strengthens the principle, that a law repugnant to the constitution is void; and that courts as well as other departments, are bound by that instrument."

The court also stated in this case that; taking an oath to uphold the constitution, and then violating that oath (by some act, or law) is violating that oath, and therefore a crime (the quoted part of this is very long so not reproduced here).

This case established that the US Constitution was the supreme law of the land and every department of government, required to take an oath of office, was bound to follow the constitution, not the law (if they are clearly set against each other). It is an example of Judicial Power to rule any law passed by the representative branch as unconstitutional, as well as any action by the Executive branch as unconstitutional: making that act void.