In an American future, the president decides, when facing military predictions of a coming conflict with China, that it is time to take power for herself. Expressing contempt for Congress, the courts, and the media, the president justifies the action on national security grounds. With these powers, the president's executive orders will now be considered supreme law, with Congress consulted on an as-needed basis. This president could be said to be leading a type of government known as

An autocracy

Explanation:

An autocracy is a type of rulership where all the powers of control and governance lie in the hands of one person, the ruler, who takes no instructions from anyone and whose actions are not regulated by the people whom he governs or by any other body.

In the question, the type of governance practiced by this American President is an autocratic one because she takes all the powers to herself, refuses regulation by congress, and issues executive orders which are now considered as the supreme law instead of the constitution in democratic climes. Congress is consulted on an as-needed basis, which means that they no longer serve an important role in the government.