Believing the government can do anything the constitution does not specifically forbid is

- Loose Constructionist.

Explanation:

A person who believes that the federal government is allowed to take rational actions which are particularly not forbidden by the Constitution would be called a 'loose constructionist'. Such a person believes in broader or wider interpretation of the words stated in the constitution but it however leads to bending or loosely interpreting the constitution which is directly in contrast to 'strict constructionist' who strictly believes that the government is responsible for taking only actions portrayed in the Constitution directly.