Which political unit has the right to make and enforce laws?

If you are speaking in the context of political science theory, then any entity which has some form of sovereignty has the right to make and enforce laws. This can be nation-states, city-states, regional or consitutent states, or even local governments.

If you are asking which parts of a government have the indicated powers, the Legislative branch has the right to make laws, and the Executive branch enforces them.