The Watergate crisis is a prime example of a president who overstepped his authority, and committed illegal acts, such as having minions break into a rival's office, covering up the break-in, and destroying evidence. President Nixon was forced to resign over his actions in this situation.
the president had overstepped his powers
A game warden does not have more authority than the president. The president is the highest authority in a country.
Yes, the president has the authority to declassify documents.
A precedent from a previous legal decision cited in a current legal decision is called an "authority". Police have authority to arrest persons who they believe have committed a crime. The President of the United States has authority to command all United States military forces.
George Washington
Ulysses S. Grant was the President when Alexander Graham Bell demonstrated the telephone. The demonstration took place in June of 1876.
Which President are you referring to? The US President has no such power. However, the President of the country in question, may be able to ban anyone from returning to the country that he pleases.
The president does have the authority to veto an existing law, but this can still be overturned.
Prime minister
constitution
the president
laws that give the president responsibilities